Circular 27 UNIVERSITY OF HAWAII AGRICULTURAL EXPERIMENT STATION Honolulu, Hawaii October 1949 FOREWORD Frozen foods offer the housewives of Hawaii the same advantages and the same problems as they do elsewhere. Many people are asking whether to buy or not to buy a freezer; how to care for and use a freezer to the best advantage; what packaging materials to use; what foods to freeze in Hawaii and how to prepare them for freezing. To aid in studies of freezing foods in the Territory, the University of Hawaii Agricultural Experiment Station has had as research con­ sultant for a period of 5 months Dr. Faith Fenton, Professor of Foods and Nutrition at Cornell University. Dr. Fenton is considered one of the foremost authorities on frozen foods in the home economics field in the United States. This circular on the selection and care of home freezers and on the selection and use of packaging materials has been prepared because of the marked interest in home freezing and storage of frozen foods in Hawaii and in response to many requests for information. Dr. Fenton's years of research and experience in the frozen food field have admirably qualified her to prepare this circular, which pre­ sents in condensed form essential information needed by the prospective buyer of a freezer and the novice in freezing foods, as well as sound advice for those who have had some experience with freezers. Directions for freezing local foods will be released in printed form as experimental work proceeds.

CAREY D. MILLER Head, Foods and Nutrition Department University of Hawaii Agricultural Experiment Station

ACKNOWLEDGMENT The author and the University of Hawaii wish to express apprecia­ tion to the Hawaiian Pineapple Company for cooperation in taking and making available the photographs used in this circular. These il­ lustrations contribute greatly to the graphic understanding of the ma­ terials and procedures described in the circular. CONTENTS

PAGE PART I. Hor.rn FREEZERS AND STORAGE CABINETS

Reasons for Buying a Freezer . 7

Reasons for Not Buying a Freezer 8 Choosing a Freezer 8 Points to Look for in Selecting a Freezer 9 Location of Freezer . 10 Use and Care of the Freezer 10 Home Refrigerators with Freezing Compartments 11 Home Refrigerators with Ice-Making Compartments 12

PART II. FROZEN FooD PACKAGING MATERIALS

Functions of Packaging Materials 13 Principles Involved 13 Requirements of Packaging Material 14 D escription of Packaging Materials 14 Packaging to Fit the Food 17 Packaging Techniques 19 Labeling Packages 21 Care of Packaging Materials 22 Cost of Packaging Materials 22 Conclusions . 23 Some Packaging Materials Available in Honolulu, June, 1949 24 A side-opening freezer filled with foods of different types. HOME FREEZERS AND PACKAGING MATERIALS

Part I-Home Freezers and Storage Cabinets

Buying a freezer represents a major investment for most families. Its pur­ chase competes with that of other household necessities or luxuries such as re­ frigerators, dishwashers, washing machines, ironers, radios, and cars. REASONS FOR BUYING A FREEZER 1. Convenience In Marketing: You have a store stocked with foods of your own choosing in your own kitchen, one that never closes. There is no guessing as to the amount you will need because frozen foods contain no waste. In Meal Preparation: You can prepare an elaborate meal entirely from frozen foods in 30 minutes with no waste entering the kitchen. The food is at hand for that unexpected last minute guest. Foods for the dinner party or tea can be prepared days in advance. In Management: Freezing foods presents one of the greatest possibilities of manage­ ment in a home. If you are freezing relatively large amounts at one time it is possible to put your work on a production line, motion-saving basis. Children and men are usually interested in helping. All of the waste from vegetables and fruits can be discarded at one time. If you are employed and the only free time you have is over the week-end, you can prepare and freeze food for a week or more. This may make it advisable for even one person living alone to own a freezer. 2. Better use of surplus foods. 3. Variety in the diet. Seasonal foods at the peak of their quality can be spread throughout the year. 4. High quality and nutritive value. Frozen foods are equivalent to and may be superior to market-fresh fruits and vegetables. 5. Home-frozen foods may have higher quality than commercial ones which are subjected to the hazards of transportation and to long storage.

7 6. Money savings are possible if you use your own surplus products, whether they be fruits, vegetables, meat, fish, wild game, or left-overs; buy sea­ sonal foods such as fruits and vegetables at their lowest prices and highest quality, and poultry when flocks are being culled; buy wholesale cuts of meat. You can save on gas or bus fares because of fewer trips to the market.

REASONS FOR NOT BUYING A FREEZER 1. If you have no place to put it. 2. If you have one of the newer refrigerators which provides a separate freez­ ing compartment ( see page 11). 3. If the initial cost, the cost of packaging materials, and the small increase in your electric bill are not worth the above conveniences and satisfactions. Frozen foods are not usually cheap on a money basis.

CHOOSING A FREEZER 1. Buy from a company that is reliable and carries a "make" that has a reputa­ tion for good quality. 2. Types Chest or Top-opening Size: Small-3 to 5 cu. ft. capacity; medium-6 to 10 cu. ft. ca­ pacity; larger, with 2, 3, or 4 compartments-8, 12, to 50 cu. ft. capacity. Primary freezing area: In the small boxes no special freezing space as such is provided. A limited amount of f1eezing may be done by placing the packages against the side walls. Some of the larger freezers have a special compartment for freezing. Convenience: Placing and removing packages involves bending and it is difficult to find them. The cold air does not "spill out." The top can be used as a table when needed. Upright or Side-opening Size: 5 to 25 and 30 cu. ft. capacity. The same capacity freezer occupies less floor space in the upright type than in the chest type. Its height above that of the chest type provides extra space. Freezing area: A more rapid freeze is possible. At least one shelf contains refrigerant which provides a primary freezing area. Sometimes each shelf contains refrigerant as well as the inner top wall. In some freezers a separate door is provided for each shelf; in some, wire baskets are provided. Utilization of space: The shelves occupy some of the space. It is sometimes difficult to utilize all of the space between the shelves. Convenience: Placing and removing packages does not require bending although reaching food on the bottom shelf may re­ quire stooping. Packages which are slippery may slip forward when the door is closed and, if there are no inner doors or bas­ kets, fall out when the door is opened.

8 Although the cold air tends to spill out when the door is opened the differences in the amount of electricity used for the rwo types of freeze£s are not very large. The upright type may re­ quire more frequent defrosting than the chest type. 3. Capacity The size advisable depends on whether the freezer is to be used for storage of commercially frozen foods only, as a supplement to the community locker, or for home freezing and storage. The usual recommendation is 3 to 5 cu. ft. per person for home freezing and storage. One cu. ft. will accommodate about 35 lbs. of food depending upon the type and shape of food. A 6 cu. ft. space will accommodate from 160 to 324 pints. If the pack­ ages are rectangular, it will hold 300 pints or 150 quarts. Round packages result in waste space. By a constant turnover of food, the amount of food stored during 1 year can be increased several times. 4. Cost The cost of a freezer is little more than that of a refrigerator of compara­ ble capacity. It varies with the manufacturer, as do refrigerators and cars, and with the capacity. The cost per cu . ft. decreases as the size of the cabinet increases. For instance, a 30 cu. ft. capacity freezer of ~ given brand costs $25.00 pe£ cu. ft. while 4-cu. ft. freezers of three companies range from $65.00 to $67.00 per cu. ft.; the costs of the 8-cu. ft . freezers put out by the same three companies range from $43.00 to $45.00 per cu. ft. In addition to cost in relation to capacity, one should also consider the following: Is installation included in the price? Is special wiring required? In general, ordinary wiring may be used for freezers up to 12 cu. ft. capacity. If the motor is more than % horse power, special wiring is needed. Are there extra charges for baskets, thermometers, alarm devices, or locks?

POINTS TO LOOK FOR IN SELECTING A FREEZER 1. Guarantees that go with the freezer. Most companies guarantee to the original buyer the entire freezer for 1 year and a 5-year protection on the mechanical refrigerator system. 2. Provision for servicing by a local and reliable company or repairman. 3. Over-all dimensions, to be sure the freezer fits into the space you have available and that it will go through the doorways to this location. The width cannot be more than 29 inches if it is to go through the ordinary door. 4. Finish, which should be rust-proof, or at least rust-resistant, and easy to clean.

9 5. Accessibility of food. In the chest type, the box should be neither too deep (not more than 24 to 26 inches) nor too wide; the opening should be large enough to remove food easily. In the upright type, the shelves should be spaced for efficient use and be of convenient depth for you to reach to the back easily. 6. No odor about the box. Sometimes the paint or finish may have an odor. 7. Insulation should be equivalent to from 4 to 6 inches of cork board in in­ sulating value. If the insulation is insufficient, moisture will condense on the outside of the box in warm, humid weather. This may result in rusting and in puddles on lids and floor and in icing of lids or doors. 8. Vapor proofing, which should protect all insulation from entrance of wa­ ter vapor from the air, both inside and outside the box. 9. Lids and doors must be well insulated to prevent heat from the room entering the box. They must fit tightly to prevent the entrance of water vapor from the room. If sweating occurs, the lids or doors may freeze shut. 10. Lids not too heavy or too large to lift with comfort. Counterbalanced hinged lids are convenient. 11. A thermometer or some device for determining the temperature inside the box. One that can be read from the outside is preferable. 12. An alarm device which warns when the temperature gets too high because of mechanical or power failure. The alarm system should be operated by batteries so that it will work even if the freezer is accidentally disconnected or if the main power supply fails. The former trouble is more likely to go unnoticed. 13. Provision for locking if desired. 14. Ability to hold low temperatures when the power is turned off. A well­ built and well-filled box should go 2 or 3 days without the contents thawing IF the box is NOT OPENED. 15. A motor that operates quietly and does not need periodic oiling. Hermeti­ cally sealed units do not need oiling and are relatively quiet. 16. Instructions for care and use of the freezer, supplied by the manufacturer.

LOCATION OF FREEZER Place the freezer so that it is convenient for use. It should not be placed near the kitchen range or where the sun will shine on it, nor should it be in a damp place where moisture condensation may cause the hardware to rust.

USE AND CARE OF THE FREEZER 1. Keep all surfaces of the freezer spotlessly clean and dry. 2. Check thermometer readings daily to determine whether the temperature has risen above zero. 3. Do not open the freezer more often, or keep it open longer, than necessary. 4. Defrost the freezer according to the manufacturer's directions. Because of the high humidity in Hawaii, more frequent defrostings are necessary

10 than the once . or twice a year which the directions usually suggest. Never permit the frost deposit on the inner walls of the cabinet to become more than % inch thick. 5. Package all food in moisture-vapor-proof materials to keep food moisture from escaping and collecting on the inner walls of the freezer. 6. Place packages in contact with the primary freezing area to obtain a rapid freeze. Leave a space between them. 7. Do not overload. Follow the manufacturer's instructions as to the maximum number of pounds of food which should be frozen in a given time. 8. Use your frozen food while it is still in prime condition. Frozen food gradu­ ally loses quality during storage. The storage life varies with the type of food. 9. Make and write down a planned program for the management of the freezer. Keep a record of your freezing, including amount of food, variety, and ma­ turity of fruits and vegetables, methods of packaging, length of storage, meth­ ods of thawing and using the frozen foods, and the quality when eaten. In this way you can improve your freezing from year to year on the basis of your own experience as well as from what you learn from others. HOME REFRIGERATORS WITH FREEZING COMPARTMENTS If you are planning to buy a new refrigerator you may wish to consider buy­ ing one that provides a separate freezing compartment. The increased kitchen space required is mostly in the height of the cabinet. The extra cost is about 10 percent of the cost of the standard refrigerator of similar construction and stor­ age capacity. Most household refrigerator manufacturers are now producing refrigerators with a freezing compartment completely separate and insulated from the fresh food compartment. In effect, this provides two refrigerators in one. The air temperature maintained in the freezing compartment is 0° F., which means that the storage life of the food should be the same as in the sepa­ rate freezer. If the temperature is higher than o° F., do not store your frozen foods long. The capacity ranges from 1 Y4 to 2 cu. ft., which probably means that the turnover of foods will be sufficiently rapid to maintain high quality. If you are using the freezing compartment for storing commercially frozen foods remember that the storage life is considerably less than that of comparable freshly frozen foods because of prior storage and handling. Some refrigerators are provided with a separate exterior door for the frozen food compartment; others have only a single exterior door providing access to both compartments. In the latter case gasketing is provided on the inside surface of the door to separate the two compartments. The freezing compart­ ment provided with a separate door will not require defrosting as frequently as will the other type.

HOME REFRIGERATORS WITH ICE-MAKING COMPARTMENTS All mechanical refrigerators at present have ice-making or ice-cube compart­ ments. These compartments are suitable for storing small quantities of frozen foods in good condition from a few days to about a week, depending on the type of food. The average air temperature is 20° F. Although the temperature

11 control can usually be turned colder, it should be done for short periods only; otherwi se the fresh fcods in the food storage section may be frozen. The bot­ tom shelf is usually colder than the upper shelves since it contains refrigerant and the upper shelves may not. In some refrigerators, a package of commercially frozen food placed on an upper shelf may thaw, while if it is placed on the bottom shelf it does not. One of the disadvantages of storing frozen food in the ice-cube compart­ ment of a standard refrigerator is the frequent defrosting necessary. The relative size of the ice-cube compartment has increased but it is still small, about 0.6 cu. ft. in a 7 cu. ft. refrigerator.

Figure 1. Left: Wrapping materials. Right:_,,,..,.,. A variety______of packing_____ cartons. ______Part II-Frozen Food Pacl~aging Materials

Packaging should not be the weak link in your freezing procedures. Often faults laid to other causes are due to poor packaging. For instance, in one com­ munity the leaking of juice from packages of frozen fruits during storage was attributed to too high a proportion of sugar to fruit. Actually the fruit and sugar were too heavy for the flimsy paper boxes used. When the same mixture was placed in sturdy cartons no leakage occurred. Poor wrapping material is one of the most frequent causes of poor quality frozen meat. Improper packaging may result not only in poor quality but also in complete loss of the food.

FUNCTIONS OF PACKAGING MATERIALS The most obvious function of packaging material is to serve as a container for the food. Its broad function is to extend the storage life of the food. Satis­ factory storage is achieved when packaging materials: Prevent or minimize loss of moisture from the food and consequent drying out. Exclude or minimize contact of the food with air, thus decreasing the sev­ eral oxidative changes which cause loss of quality ( see p. 20). Prevent absorption of exterior odors and flavors. Protect food from dirt, insects, and bacterial and mold contamination before and during storage and also during thrawing. The package itself should be protected from contamination prior to use. PRINCIPLES INVOLVED Conditions in the box : The conditions in low-temperature storage are such that they result in drying out of the food unless the foods are packaged correctly. This is illustrated by the experience of the small boy who thought it would be fun to surprise his playmates with snowballs on the Fourth of July. He care­ fully deposited the snowballs, unwrapped, in the new freezer. When he checked on them in a few weeks he found none there. They "had evaporated in thin air," that is, the dry air of the box had absorbed them and gradually de­ posited them as frost on the inner walls of the box-most heavily on the walls containing refrigerant which were the coldest. The circulating air in a low-temperature box is very dry, that is, the hu­ midity is low. This is because the temperature of the air in the box is so much higher than the temperature of the cooling areas, the walls containing the refrig­ erant, and the freezing plate. As a result, the air upon striking these areas gives up much of its moisture, which is immediately condensed upon the cooling surfaces as frost. Naturally, the air will then pick up moisture from the stored food that is not properly packaged. This results in drying out or desiccation of the food. The surface drying of meats and poultry is often called "freezer burn." This occurs before rancidity is noticeable. 13 The rate of evaporation is affected not only by the vapor-proofness of the packaging material and the efficiency of its closure but also by the storage tem­ perature and the relative humidity. The rate of evaporation varies directly with temperature. T emperature: Air at 15 ° F. has about twice the drying action of air at o0 F. at the same humidity. Air at 0° F. has almost three times the drying action of air at - 20° F. Since o° F. is the temperature of most home freezers the packaging is extremely important. H u111idity: The rate of evaporation varies inversely with the relative hu­ midity. The evaporation process results from a natural tendency to establish equilibrium between the moisture content of the air and the moisture content of the food. The more humid the air the less the evaporation from the food, other things being equal. Since little can be done about the humidity of a home freezer, the packaging is extremely important. Air motion: The rate of evaporation increases directly with the rate of air circulation. Therefore circulation should be kept to a minimum in the storage compartment. Food which has been frozen in a freezing compartment provided with a fan should be removed to the storage compartment before the fan is turned on for freezing the next lot of food. If a packaging material permits moisture to pass out it will also permit air, odors, and flavors to pass in. Since air contains oxygen, its presence permits oxidation, the reaction of a compound with oxygen. Many of the undesirable changes during the storage of frozen foods are due to oxidation. These include loss of flavor, aroma, color, and texture, and the development of rancidity. Ascorbic acid, or vitamin C, and vitamin A are among the nutrients which are destroyed by oxidation. The importance of keeping oxidation to a minimum and of preventing the absorption of odors and flavors is obvious.

REQUIREMENTS OF PACKAGING MATERIAL Packaging materials should be: 1. Moisture-vapor-proof to prevent not only loss of moisture, aroma, and flavor but the entrance of air, odors, and flavors. They should allow a tight closing or seal. 2. Waterproof, with a shape and seal to prevent leakage. 3. Physically tough to withstand handling, stacking, and puncturing. They should not become brittle or crack at the low temperature of the freezer. 4. Greaseproof if the food is a fatty product. 5. Physically inert so that it will not impart odor or flavor to the food. 6. Easy to handle, that is, easy and efficient to fill or wrap, to seal, to label, and to empty or unwrap. 7. Space-saving in storage prior to use and in the freezer. ~

DESCRIPTION OF PACKAGING MATERIALS There is no packaging material that is best for all frozen foods. Some are best for one type of food and others are best for another. Therefore in selecting packaging material it is advisable to have in mind the food which you wish to freeze and also the amount you wish to freeze in one package. Much yet re­ mains to be done in the standardization of package sizes. 14 The wrapping materials man ufactured at present include: 1. Sheetings Cellophane, a special moisture-proof type which can be heat-sealed. Paperboard, specially waxed. Aluminum foil. This is pliable and ca n be fitted fairly snugly to the shape of the food. Pliofilm, a transparent rubber material which is not appreciably affected by low temperatures. Polyethylene wrap, a transparent plastic material which will stand more handling at low temperatures than cellophane or pliofilm. Vegetable parchment paper, specially coated. Laminated ( fused together) papers. Various combinations of paper, metal foil , g lassin e, cellophane, and rubber latex sheets. 2. Bags Bags are now manufactured in most of the sheeting materials de3cri bed above. Some of these are duplex bags, that is, they consist of a liner and an exterior bag. Bags made of parchment paper, or of speci:illy treated sulfite paper, can be used by themselves. Transparent bags made of cellophane, glassine, or pliofilm are so fragile that they re­ quire some outside protection such as a carton or stockinette. 3. Cartons and Containers A. Rectangular Folding waxed pasteboard cartons with bag-liners. These are avail­ able with top openings or end openings. They are made in small-V2 to 1 lb.; medium-2V2 lb.; and large-5 and 10 lb., sizes. The minimum depth package within the limits of rigidity is best for rapid freezing. Some of these boxes do not require liners. Two-piece pasteboard containers. The top is put on as a tele­ scoping cover. They are ordinarily used with a heat-sealed, vapor-proof, inner bag. Aluminum Traypak, one of the newer packages for frozen foods. These packages are rectangular in shape and have

Figure 2. Left: Fruits to which sugar or sirup has been added require sturdy packages. Right: Fruits which tend to float can be kept below the surface of the sirup with crushed waxed paper. The surface of purees can be protected with cellophane or pliofilm cur to fit. about the same dimensions as the small 10- to 12-ounce rectangular pasteboard cartons. Before use the aluminum cartons and the lids nest separately. The carton is made of a single sheet of pure aluminum with no seams. It is easy to fill and fairly simple to close. A short metal bar is provided to seal the edges, with a wooden block to hold the lid in place during closing. Food freezes more rapidly in these containers because the metal permits more rapid heat trans­ fer than do paper and glass. The one disadvantage is that at present the seal cannot be made entirely perfect. B. Cubical Containers Specially treated pasteboard. The top consists of four sections which are extensions of the four sides. Each of these is sealed in place, one on top of the other, with a warm iron. They are sturdy, easy to fill and to empty, and do not allow waste space in the freezer. They cannot be nested when not in use, however, and the sealing compound sometimes drops down on the surface of the food. Some of the cubical con­ tainers are provided with metal slip-in lids. A plastic container is now available for frozen foods. It is tall and cubical in shape with a set-in lid. C. Tub, cylindrical, or cup type Pasteboard. Lily-Tulip, Sealright Cold Spot, and Dixie cups are examples of this type. Buy the heavily waxed type; the stand­ ard ice cream containers are not moisture-vapor-proof. These containers nest and so do not occupy much storage space prior to use. They do not require setting up as do the folded rectangular type, and are easy to fill and empty. The two types of lids are the snap-in and the over-closure or friction type. Glass freezing jar. A glass jar, designed specially for freezing, is made in 16- (1 pint) and 22-ounce sizes. The jars are larger at the top and taper slightly to the bottom; thus there is no shoulder to retard the removal of the food. It is not necessary to thaw the food in order to remove it from the jar. The jar is made with nonslip, stippled ribs. The one­ piece reusable aluminum cap is recessed so that jars stack easily either in or out of the freezer. The label can be writ­ ten on the lid. Another advantage is the transparency of the glass. The jar is easy to fill and empty, and can be sterilized and reused indefinitely. Breakage can be kept to a minimum by allowing sufficient head space. There is no pos­ sibility of the food absorbing flavors or odors from it. The jars are heavy and cannot be nested as can the paper tubs. Tin cans such as are used for canning foods are also satisfactory for frozen foods. A can sealer, however, is necessary. All of the cylindrical type cartons have the advantage of being relatively sturdy, leak-proof, and easy to fill and empty. The common disadvantage is that all round containers allow waste space in the storage compartment of the 16 freezer. The rate of freezing is also likely to be slower since the distance from the center of the package to the outside is greater than it is in the flat, rectangu­ lar boxes. Furthermore the contact of the package with the primary freezing area is less. D. Miscellaneous Plastic containers made for ordinary food storage may be used for short storage providing care is taken about sealing. They are available in several sizes and shapes with several types of closures. They are transparent, light in weight, and easily labeled. They are easy to fill and empty and can be reused. Immersion in scalding hot water may cause them to warp. Paper pie-plates with metal rims are suitable for freezing un­ baked fruit pies.

PACKAGING TO FIT THE FOOD As stated previously, no one packaging material is best for al l types of food. 1. Fruits: Fruits usually contain considerable liquid either in the form of added sirup or in juice drawn from the fruit by the added sugar. This liquid is likely to remain in the liquid state at 0° F., or even lower, be­ cause dissolved sugar markedly lowers the freezing point of water. Heavy sirups do not freeze in the standard home freezer. Therefore it is essen­ tial that the carton used for freezing fruit be leak-proof. Sugar in itself is heavy and consequently the fruit-sugar and the fruit-sirup mixtures re­ quire sturdy packages. Furthermore fruits, unless they are to be cooked, require defrosting before serving. It is essential that this be done in the sealed original package to prevent exposure to the air. For these reasons the sturdy pasteboard and glass cylindrical packages have proved satis­ factory for frozen fruits. The cubical shape is also satisfactory although

Figure 3. Fruit and vegetable purees and concentrated soups may be frozen in the ice­ cube tray, then wrapped, packaged, and stored. 17 Figure 4. Left: A funnel keeps sealing surfaces clean and dry. Right: A cloch-covered block makes heat-sealing of inner bags easy.

sometimes it is difficult to empty. The aluminum Traypak rectangular packages show promise for frozen fruits, as do also the plastic con­ tainers. Fruit sauce and fruit purees may be frozen in individual serv­ ing amounts in some of the plastic containers and also served in them. Small cubes of purees frozen in ice-cube trays may be wrapped individually in pliofilm or ce llophane and then placed in a larger carton for storage. These cubes are convenient for use in beverages. The surface of the puree in the ice­ cube trays should be tightly covered during freezing and each cube should be wrapped tightly for storage. Cubes of concentrated soups ca n be frozen the same way. 2. Vegetables : Vegetables require blanching and chilling prior to freezing, and are wet when placed in the package. Packing vegetables in brine has been practically discontinued, so there is never any large amount of I iquid. The recommended packages for vegetables include: Rectangular folding waxed pasteboard cartons End-opening provided with a bag-liner Top-opening provided with a liner Rectangular, heavily waxed pasteboard containers with overlapping closures and with reusable plastic lids Aluminum Traypaks H eavi ly waxed, cubical, tub, and cup-shaped containers Glass freezing jars Plastic containers 3. M eat, Poultry, Fish, and Game : Wrapping or sheeting material is prob­ ably most su itable for the packaging of meat, poultry, fish , and game because it can be more eas ily molded to the irregular shapes of these

18 foods. The wrapping may be any of those listed previously. If you use cellophane or pliofilm, protect the package further by placing it in stock­ inette, which can be purchased by the roll in tubular form. Stockinette not only protects the paper from tearing but helps to keep the paper tight against the surface of the meat, thus excluding more air. Some light-weight papers require a double wrap ; a single wrap of a good paper is more satisfactory. Aluminum foil is suitable for meat, poultry, fish, and game because it can be pressed snugly around and against the surface of the food. It also permits a rapid heat transfer. In packaging meat and poultry remove any sharp bones which might puncture the wrapping. Pasteboard cartons measuring 4 x 6 x 1% inches are suitable for ground meat and fish . Larger ones, 8 x 10 x 2 inches, are best for steaks, chops, and cut-up poultry.

PACKAGING TECHNIQUES 1. Have the proper packaging materials and sealing and labeling equipment at hand and arranged conveniently before starting the preparation of the food. 2. A funnel specially suited to the type of container aids in filling and also in keeping the sealing surface clean. A rectangular funnel with a stand to support it is convenient for cartons with bag liners. Paper or ca rd­ board funnels can be improvised for temporary use. A round wide­ mouthed funnel is suitable for cylindrical containers. A round funnel may be made by removing both ends from a tin can. One end may also be shaped into an oblong funnel. 3. Use a package which will hold just enough food to satisfy the family needs for one meal. Small packages freeze and thaw more rapidly than do large ones. Furthermore, leftover frozen food loses quality on standing because freezing softens animal tissue and most plant tissues. A second package can be opened when necessary. 4. If you put more than one cut of meat, poultry, fish , or game in one package, place two layers of paper between the pieces to make separation without thawing easier.

Figure 5. The drugstore wrap. Left: The meat is placed in the center of the paper and the two sides are brought together in a druggist's fold. Right: The fold is pressed tightly against the meat, and the ends are folded in snugly, pressing out the air. The pointed ends are folded under, and the package is then tied or sealed and labeled. 5. Leave enough air space to allow for expansion during freezing. The more water present the greater will be the increase in volume during freezing . The greater the surface area in proportion to the depth of the package the less air space is required. If not enough air space is left in a glass jar, breakage is apt to occur. You can soon learn by experience how much air space should be left for each kind of food in each kind of container. It is probably as bad to leave too large as too small an air space. Most materials except glass expand somewhat under pressure of the expanding ice. 6. Keep the amount of air entrapped in the package to a minimum. Drying takes place in crevices and air pockets. This internal drying results in a heavy deposit of frost, sometimes called "cavity ice," on the inner lining of the package and around the food particles. Temperature flu c­ tuation is the chief cause of the transfer of moisture from the food to the entrapped air. The moisture is not drawn out of the package if the package is completely moisture-vapor proof. Elimination of air is also important in preventing the undesirable oxidative changes previously mentioned (page 13). Sometimes it is advisable to press a piece of cellophane or pliofilm ( cut to fit) firmly over the surface of the food in a carton. Take this precaution if you are not sure your seal is airtight. Often fruit which tends to float can be kept beneath the surface of the sirup by placing a piece of crushed waxed paper on the top before ad j us ting the cover. Minimizing the amount of air means: not leaving too large an air space for expansion; in some cases, cutting vegetables into smaller pieces to permit a more compact pack; covering fruits with sugar and their own juices or with sugar sirup; blanching some fruits to drive out the inter-cellular air; pureeing some vegetables and fruits to permit a more compact pack. Care must be taken, however, to prevent the incorpora­ tion of much air during pureeing. 7. Fit wrapping materials snugly against the surface of the food. 8. See that the seal is as airtight as possible. A poor paper with a good seal may be as effective in maintaining quality in the frozen food as a good paper with a poor seal. Best ~esults are obtained with a good paper and

Figure 6. The butcher's wrap. Left: The meat is placed near a corner of the paper, the corner is folded over the meat, and one side of the paper is folded across. Right: The package is then rolled over half way, and the ocher side is folded across. (See Figure 7 for completion of chis wrap.) a good sea l. Press out as much of the ai r as possible from the package before sealing it. Be sure the sealing surfaces are clean and dry. Heat Sealing: Cellophane and pliofilm may be heat-sealed with a warm flat iron, curling iron, or one of the new electri c hand sealers specially made for this purpose. A cloth-covered block makes heat-seal­ ing easy. It can be made of metal or wood and shou ld be the proper height. Stand the ca rton upright alongside the block. Place the top of the bag liners on top of the block for seali ng. Seal ing Tape: Several types of sealing tape are ava il able. Choose one that does not crack or loosen at low temperatures. The coating on the tape should not carry any odor. Stockinette: Slip the stockinette over the cellophane-wrapped pack­ age. Tie the cut end of the stockinette. Pull the other end tightly over the package and cut the stockinette, leaving only enough to ti e firmly. Wrap fruit pies in cellophane and insert in stockinette. 9. The drugstore wrap and the butcher's wrap are often used for wrapping meat, poultry, fish , and game. The drugstore wrap usually requues Jess paper, permits a tighter seal, and makes a neater package than does a butcher's wrap. The butcher's wrap is preferred with an inferior wrapping paper because the paper is wrapped around the food several tim es. For the druggist's wrap, place the food in the center of the paper. Bring the two sides of the paper evenly together at the top. Make a druggist's fold. Continue the fold tightly against the product and press it flat against the product. Fold the ends in, pressing out the air as you do so . Then fold the ends under the package. Next fold the pointed ends under. Wrap string around the package both ways and ti e it ti ghtly, or heat-seal, or seal with gummed tape. (See Figure 5.) For the butcher's wrap, place the meat in one corner of the paper. Fold the corner over the meat and then fold one side across the meat. Roll the package over half way and then fold the other side of the paper across the meat. Roll the package over to complete the wrap. Fold under the pointed end to give a better seal. Tie with string, heat-seal, or seal with gummed paper. ( See Figures 6 and 7.) LABELING PACKAGES Label all packages clearly and completely. The date wrapped, the kind of food , the pretreatment if any, and the weight or vo lume should appear on all

Figure 7. The butcher's wrap is completed by rolling over the package and sealing ic or eying ic with sering. It should then be labeled clearly and completely. labels. For fruit, include the variety, the maturity, and the pretreatment such as blanching or pureeing and the addition and amounts of sugar, sirup, ascorbic acid, and citric acid. For vegetables, include the variety, maturity, cutting or pureeing, and method and time of blanching and of cooling. For meat, include the kind (beef), the cut (sirloin) or the number of cuts ( 4 loin chops); for poultry include the kind (chicken), the type (fryer) ; for fish, species ( mahi­ mahi), the type (fillet) , and number of pieces ( 4 fillets) ; for game, the kind (rabbit) and the number. Be sure the label is one that will not be lost and that can be easily read. Different colored cord can be used to identify different types of food quickly. Write labels on glass, plastic, and similar containers with a glass-marking pencil ( 10 cents at drug and dime stores) . Several marking pencils or pens made specially for the purpose are now available. Many of the cartons have special places for labeling. A tag is usually necessary for wrapped meats, poultry, fish, and game. Either tie it to the package or place it under the stockinette. In using metal foil, you may write the label on the foil with a china-marking pencil before you start wrapping it around the food. CARE OF PACKAGING MATERIALS Keep rolls of wrapping paper such as cellophane, pliofilm, parchment, and similar papers in a cool place that is not too dry. The treated layers on them have a tendency to crack if they become very dry. Bags require special care because creasing tends to break the treated layers. Bags and boxes also tend to give way or collapse at the creases. Do not purchase such large amounts of paper packaging materials that it is necessary to store them for long periods of time before you use them. Protect wrapping paper and paper cartons from contamination. Glass jars and plastic and aluminum cartons can be easily cleansed just before use. Keep everything about frozen foods as sanitary as possible ! COST OF PACKAGING MATERIALS Beginners in home freezing are apt to be hesitant about expenditures for the proper packaging materials for their frozen foods and are apt to resort to such materials as they have on hand, such as ordinary waxed paper, butcher's paper, and ordinary ice cream containers. These were early shown to give in­ adequate protection against deterioration of the food. Often the price of the food lost may amount to many times the price of proper packaging. The cost of proper packaging material may be greater than the cost of the electricity required. However, many prospective home freezer owners are con­ cerned about the electricity but give little planning to the cost and selection of packaging material. There is a considerable price range in wrapping materials and in cartons. The initial cost of paper containers is less than that of aluminum, glass, plastic, or tin. Paper, however, is not as good a conductor of heat as aluminum and tin nor can it be used as many times. The end-fill paper carton costs a little less than the top-fill type. In deciding on cost of packaging materials consider the following: 1. Will the packaging material protect the food from deterioration when it is properly sealed? Poor packaging material is not cheap at any cost. 22 2. Is it suitable for the particular food for which you are purchas ing it ? 3. Is it easy to use, that is, is it easy to fill, seal, label, and empty? Your time and nervous energy may have some money value. 4. Can it be cleansed? If not, is it fairly sanitary as purchased ? 5. Can it be reused indefinitely or at least several times ? Glass jars are durable and can be used indefinitely. Plastic containers, aluminum cartons, and tin cans may also be reused a number of times. Aluminum foil can be reused providing no pin holes are visible when you hold the foil up to the light. 6. Does it have any other use than as a container or wrap for frozen foods? The many uses of glass jars and tin cans are well known. Plastic con­ tainers can be used as refrigerator dishes and the small ones can often be used as serving dishes for the fruit or salad which has been frozen in them. The aluminum Traypak can be used to reheat the frozen food. It can also be used for baking. Aluminum foil , even though it has pin holes in it, can be washed off and used for wrapping food to be stored in the refrigerator for short periods. 7. Do you have proper and sufficient storage space for the packaging material when it is not in use? CONCLUSIONS Freezing and storage do not improve the quality of any food. It is possible, however, to have not only good but excellent frozen products with most foods. To obtain the best results, it is necessary to have not only foods of initial high quality, but also appropriate packaging materials, a sufficiently rapid freez­ ing rate, and the right storage temperature. In addition, correct techniques are necessa ry all along the line from the food source- gard en, orchard , stock farm , poultry farm, or fishery- to the dining table.

Figure 8. Meat and poultry should be given extra protection. Left: Cellophane­ wrapped meat is inserted in stockinette. Right: Poultry may be wrapped in metal foil using the drugstore wrap. 23 SOME PACKAGING MATERIALS AVAILABLE IN HONOLULU IN JUNE, 1949

APPROXIMATE TRADE NAME SIZE PRICE

I. Wrappings A. Cellophane Zer-0-Rap ...... 18 in. X 100 ft. $1.75 Zer-0-Rap ...... , . . .. , . . . 20 in. X 100 ft. 1.85 Zer-0-Rap ...... 24 in. X 100 ft. 2.25 Sylvania ...... 18 Ill. X 100 ft. 1.75 20 Ill. X 100 ft. 1.59 B. Vegetable Parchment 1. Zer-0-Par ...... , .. . 18 in. X 100 ft. 1.90 24 in. X 100 ft. 2.30 24 in. X 100 ft. 2.09 C. Laminated Papers 1. F reeztex ...... 18 in. X 100 ft. 2.98 2. KZP Co. Wrapping ...... 15 in. X 70 ft 0.59 3. Cold Spot Wrapping ...... 18 in. X 100 ft. 3.19 D . Pliofilm (synthetic rubber wrapping) 12 in. X 35 ft. 0.69 18 Ill. X 65 ft. 1.59 E. Aluminum Foil 1. Frozen food wrap ...... 18 Ill. X 50 ft. 1.89 2. Foilrapp ...... 18 Ill. X so ft. 2.30 F. Polyethylene plastic wrap ...... 18 in. X 75 ft. 1.65 II. Cartons A. Paper 1. Rectangular fo lding a. Zer-0-Pak (fully waxed inside 1.22 and out with cellophane bag) package of 25 qt. 1.5 3 package of 2 5 pt. 0.98 package of 2 S b. Cold Spot (fully waxed inside 1 qt. 1.3~ and out with Mara-Pak lam­ package of 2 5 inated bag) 2 qt. 1.19 package of 12 2. Tub Shape a. Dixie Heavy Duty Pac-Kups .. Yi pt. 23.95 (linerless, round, paraffin-coat­ package of 1000; ed, tapered tubs) 100 in a tube at 2.99 per 100 Slip-in tab lids for Pac-Kups .. 5.90 package of 1000; 100 in a tube at 0.74 per 100 b. Lily-Tulip Cups and lids . .... pt. 1.35 (linerless, round, paraffin-coat­ package of 2 5 ed, slip-in lids; nesting) 1 qt. 1.49 package of 15 24 APPROXIMATE TRADE NAME SIZE PRICE

c. Cold Spot Pail Pack ...... pt. 1.35 package of 2 5 qt. 1.29 package of 15 d. Oaken Bucket ...... pt. qt. B. Glass freezer jars ...... pt. (16 oz.) 0.25 each 3.00 doz. 22 oz. 0.30 each 3.60 doz. C. Plastic with covers for short storage* 1. Individual serving ...... diam. 3 in., depth 2 for l')l,i m.; ¥, cup 0.15 2. Sandwich tray (sufficient for 4 servings of frozen salad) ...... 4% in. x 4% m; 111,i cup 0.20 each III. Bags, Paper Frostofold ...... qt. l.10 package of 50 6 lb. poultry bag 0.65 package of l 0 Cellophane bags ...... Medium size 0.90 to 51/2 X 21/,i X 8 0.98 package of 5O Large size 1.09 51/,i X 21/,i X lO~'z package of 50 51/,ix2Ysxl3 1.25 package of 50 Very large size 1.09 8 X 3 X 15 package of 25 Cold Spot Mara-Pak ...... 1 pt. 0.55 package of 2 5 qt. 0.69 package of 25 2 qt. 0.55 package of 12 25 qt. 0.69 package of 1 Laminated bags ...... Medium 1.98 5I/2xl1/2xlO package of 50 Very large 2. 19 9% X 21/z X 151/2 package of 2 5 121/,i X 6 X 221/2 1.79 package of 10

*Not made specially for frozen foods; seals are not perfect. Cut cellophane, pliofilm, or polyethy­ lene to fit, and press snugly against the top surface of the food. 25 APPROXIMATE TRADE NAME SIZE PRICE

Foilrapp bags ...... 1 qt. 0.07 each Zer-0-Bags ...... 4-serving size 0.02 each 6-serving size 0.025 each Extra large 0.06 each IV. Kits A. Frostofold Frozen Food Kit...... 5.95 25 prelined pint pasteboard cartons 25 prelined quart pasteboard cartons 75 ft. polyethylene wrap 50 ft. roll stockinette 10 6-lb. cellophane bags 2 pasteboard funnels B. Zer-0-Pak Locker Kits ...... 10.50 1. Senior 1 roll Zer-0-Paks ( specially coat­ ed, white vegetable parchment) 24 in. X 100 ft. roll Zer-0-Net, stockinette tub­ ing, 100 ft . Zer-0-Pak: fully waxed inside and out, rectangular folding box with cellophane bag, 50 ll/3 pt., 50 1 qt. 2 pasteboard funnels 5 Zer-0-Bags, extra large 2. Junior ...... 5.50 Same items as above, with half the number of each item V. Miscellaneous A. Stockinette tubing 1. Zer-0-Net ...... 50 ft 0.75 2. Zer-0-Net ...... 100 ft. 1.45 3. Adler Frostinette ...... 50 ft 1.00 4. Frostofold ...... 50 ft 0.85 B. Cold Packaging tape, Permacel .... . 36 yds. 0.98 C. Thermostatically controlled electric heat sealers 1. Zer-0-Sealer ...... 3.85 2. Dobeckmun ...... 7.95 D . Quick-Fill aluminum funnel with stand ...... 0.98 ... E. Frost Scraper-Cold Spot...... 1.39 F. Freezer alarm bell ...... 7.95

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