Frying Performance of Processed Rice Bran Oils Effect of Packaging
Frying performance of Effect of processed rice bran oils packaging materials and The rice bran oil (RBO) contains types – chemically refined RBO (cRBO) high levels of phytosterols, gamma- and physically refined RBO (pRBO). storage oryzanol, tocotrienols as well as The scientists at Department of tocopherols and it extends the shelf-life Lipid Science and Traditional Foods, conditions on of snack foods. The high oxidative stability Central Food Technological Research sunflower oil of RBO makes it preferred oil for frying Institute, Mysore investigated the frying and baking applications. The saturated, performance of the RBOs compared to quality monounsaturated and polyunsaturated sunflower oil. During experiment RBO of The scientists at Turkey have fatty acids in RBO are in the ratio of three brands – two physically refined oils evaluated the effect of packaging approximately 1:2.2:1.5 and the major (pRBO1 and pRBO2) and one cRBO – materials and storage conditions on fatty acid compositions are not influenced were used in this study. A market sample sunflower (Helianthus annuus by storage temperature, although linolenic of sunflower oil was also used side by side Linn.) oil quality. During experiment acid level decrease by approximately 50% as a control for deep-fat frying. Bhujia glass and polyethylenterephthalate (PET) during storage. The oils are stabilized by (a traditional snack in India) was prepared bottles filled with sunflower oil were addition of approximately 2-5% by weight in the oils specified at 18°C of three stored under both light and dark and of RBO, which is processed to retain batches (100 g wet raw material/batch) with/without headspace to determine the unsaponifiable matter. The stabilized oil each using 500 g of the oil for frying. The effects of light, air, packaging materials may be useful as a spray oil for crackers, stainless steel pan used for frying had an and storage time on the stability of nuts, chips and other snack foods. area of 121m2 and a depth of 12.5cm. sunflower oil. Peroxide value (PV), free Blending of one oil with another oil Oils after frying had deeper fatty acids, soap content and iodine (especially RBO) has also been found to colour (23.9-137.5% increase) and higher number were measured to determine improve the stability of the blend during peroxide (101.4-274.3% increase) and stability of sunflower oil every 3 months frying and storage. The improved frying free fatty acid values (−4.7 to +27.3% until 9 months. Glass bottles recorded stability of low linolenic acid soybean oil change) compared to the starting oils, but lower oxidation values than oils compared to normal soybean oil has also the RBOs studied showed lesser changes packaged in PET. The oxidation been reported. compared to the control. Oil in the proceeded faster in packages stored in RBO is a nutritionally superior Bhujia was slightly lower (−7.9%) for a light than in darkness, and in those with oil compared to other common vegetable low-oryzanol cRBO while it was slightly headspace. The best quality oil was oils. The oil has minor components such higher (+7.0%) for a high-oryzanol pRBO. found stored in the dark, free of air and as oryzanol, phytosterols, tocotrienols, Both showed mild foaming compared to packed in glass and then in PET. Even tocopherols and squalene which show the control sunflower oil while retaining though glass gave the best protection cholesterol-lowering and skin-improving oryzanol in the oil and bhujia during against oxidation, PET bottles offer effects in addition to antioxidant effects. frying (when partial acylglycerols caused adequate protection (especially in the Presence of oryzanol and higher amounts some foaming). The bhujia retained the dark). This study showed that air, of unsaponifiable matter (such as RBO’s healthy oryzanol [Gopala Krishna AG, packaging and storage time all have an phytosterols) are unique to RBO. Khatoon S and Babylatha R, Frying performance of effect on the stability of sunflower oil Produced in India, RBO is available in two processed rice bran oils, J Food Lipids, 2005, [Kucuk M and Caner C, Effect of packaging 12, 1-11]. materials and storage conditions on sunflower oil quality, J Food Lipids, 2005, 12(3), 222-231].
Vol 4(6) November-December 2005 509 Oil/Fats
Deterioration of oils due to air, light, heat and deep-frying may be reduced with antioxidants It is obvious that prolong [Camellia sinensis (Linn.) O. fatty acid increased with increase in time exposure of oil to air and light initiates Kuntze], and different purified phenolic of deep-frying. Deep-frying of French fries deteriorative changes in the oil owing to acids, viz. ferulic, caffeic, vanillic and in corn oil was also carried out in oxidation even at close to room gallic as antioxidants. presence of caffeic, ferulic, vanillic acid temperature (30°C). Deterioration rate To follow the relative rate of and crude tea extract as antioxidants. All becomes very fast in frying oil not only oxidative deterioration of edible oils, antioxidants effectively reduced the owing to oxidation but also due to refined olive, corn and soybean oils were oxidation rate in the oil as detected by hydrolysis, as evidenced by increased free analyzed periodically for their peroxide decreases in PVs and p-AVs and relatively fatty acid (FFA) with frying time. value (PV), p-anisidine value (p-AV) and low reduction rates in IVs for all the frying Deteriorative changes in frying oil not only iodine value (IV) following exposure to times. The order of antioxidative activity depend upon the percentage moisture and air and air-light for 30 days. Changes in was caffeic acid >vanillic acid >ferulic thermal conductivity of fried food, but the above values of the oils were also acid >tea extract. Variation in percentage also upon the fat content of that food. examined and after being used for deep of FFA of corn oil due to variation in nature A study was conducted by frying of French fries at 180°C for varying of fried food was also analyzed. Percentage researchers at Department of Food Science periods of time i.e. 30, 60 and 90 minutes of FFA of the oil used for deep frying of and Technology, University of Karachi, PV and p-AV values increased in the order, chicken drum sticks were higher than the Karachi, Pakistan to follow the oxidative deep frying>air-light exposure>air values of the oil used for deep-frying of deterioration of oils exposed to air, air- exposure, while the values with respect to French fries [Naz Shahina, Siddiqi Rahmanullah, light and deteriorative changes subsequent the oils increased as soybean>corn>olive. Sheikh Hina and Sayeed Syed Asad, Deterioration to deep-frying. Furthermore, decline in Decreases in IV followed the same pattern, of olive, corn and soybean oils due to air, light, the rate of oxidation was noted following i.e. deep frying>air-light>air and heat and deep-frying, Food Res Int, 2005, 38(2), 127-134]. addition of plant extracts, such as tea soybean>corn>olive. Percentage of free Electrolyte degumming of non-hydratable gums from selected vegetable oils The scientist at Department of removed without the use of phosphoric chloride and 0.5% of sodium chloride in Lipid Science and Traditional Foods or citric acid. Acid degumming is a ratio of 95:5 (v/v), yielded degummed Central Food Technological Research associated with oil loss (∼10%) due to soybean, rice-bran and mustard oils with Institute, Mysore has developed a the emulsifying nature and subsequent phospholipid contents as low a 0.05, 0.06 new degumming protocol by employing washings. However, physical degumming and 0.02%, respectively. Gums recovered electrolyte solutions to remove with electrolyte solutions, when through this technique can easily be non-hydratable gums from soybean, rice combined with water degumming, regenerated and used for commercial bran and mustard oils. It removes removes nonhydratable gums with much purposes [Nasirullah, Physical refining: Electrolyte non-hydratable gums, mostly less oil loss (∼ 4%). The water-degummed degumming of non-hydratable gums from selected phosphatidic acid (PA) and phosphatidyl vegetable oils, when treated with 2% of vegetable oils, J Food Lipids, 2005, 12(2),103- ethanolamine (PE), which is left out after electrolyte solution, prepared by mixing 111]. water degumming and could not be aqueous solution of 1.5% of potassium
510 Natural Product Radiance Oil/Fats
Preparation of canola protein materials using membrane technology Rapeseed is an important oilseed diafiltration (DF) and drying. The highest activity and foaming properties. crop and ranks second in the world protein yield was obtained by alkaline The program demonstrated the production of oil bearing seeds. The extraction at pH 12.0 with all meals feasibility of producing food-grade protein usefulness of rapeseed/canola as a source investigated. The maximum yield of isolates from Iranian rapeseed/canola of food proteins is severely restricted by the precipitated protein was observed at pH varieties, by adapting the membrane-based presence of undesirable components such values between 4.5 and 5.5, depending on technology developed at the University of as glucosinolates, phytates and fibre (hull). variety and dehulling treatment. Almost 90% Toronto. The optimal pH for the extraction These toxic and antinutritional compounds of the proteins were recovered in three of proteins from all meals tested was in rapeseed/canola must be removed as products: PPI and SPI containing (81-98% determined to be 12.0. The precipitation curves completely as possible, before it can be used protein, N*6.25), and the meal residue (35% of all meals showed a broad precipitation as a protein source for human consumption. protein). The glucosinolate content of all maximum at pH values between 4.5 and 6.0. Suitable conditions for the meals tested and their protein products was More than 60% of the protein present in the extraction and precipitation of proteins from low, and in some cases they were below the meal was recovered as protein isolate. The Iranian canola (Brassica napus Linn. cv. detection limit of glucosinolates. Both isolates isolates had low phytic acid and glucosinolate ‘Quantum’, ‘PF’, and ‘Hyola’) meals were were low in phytic acid. Some functional content. The phytic acid level in SPI was determined by researchers of Iran using a properties (protein dispersibility index, water undetectable. All rapeseed products tested membrane-based process which consisted absorption, fat absorption, emulsifying were superior to soybean meal in fat of extraction of hexane-defatted canola meals activity, and foaming properties) were absorption, emulsifying activity and foaming at pH 9.5-12.0 and precipitation, at pH values evaluated. Iranian canola meals were properties [Ghodsvali A, Khodaparast MH Haddad, between 3.5 and 7.5, to recover a compared with soybean meal in terms of Vosoughi M and Diosady LL, Preparation of canola precipitated protein isolate (PPI). Acid functional properties. All canola meals tested protein materials using membrane technology and soluble protein isolate (SPI) was then showed a high PDI and WA and were superior evaluation of meals functional properties, Food prepared by ultrafiltration (UF) followed by to soybean meal in fat absorption, emulsifying Res Int, 2005, 38(2), 223-231]. Thermal behaviour of mango seed almond fat and its mixtures with cocoa butter
Vegetable fats and oils are widely cluding thermal behaviour, by differential ?24.27°C with a ∆Hc of 56.06 J/g and melts used in the food, pharmaceutical, cosmetic scanning calorimetry of mango seed almond between −17.1 and 53.8°C, with fusion and chemical industries and are normally fat (MAF), alone and in mixtures with cocoa maxima at 18.54°C and 40.0°C for the α obtained from oilseeds such as sesame seed, butter (CB). Results showed that mango and β polymorphic forms. Their fusion en- soy bean, cotton seed and oil. But the identi- almond seeds contain about 5.28-11.26% thalpies are 70.12 and 115.7 J/g. The MAF fication and application of new materials is (dw) of fat. The refraction index is 1.466, solids content profile is very similar to that of important for the development of new tech- the saponification index 189.0 and the CB, both in stabilized and non-stabilized nological approaches towards the use of tra- iodine index 41.76. Fatty acids found in MAF samples. The mixing compatibility was ana- ditional raw materials. Among these fat and are oleic, stearic and palmitic acids (40.81, lyzed using isosolids curves of mixtures of oil sources, cocoa butter (CB) is highly ap- 39.07 and 9.29% (w/w), respectively) as well different compositions [Solís-Fuentes JA and preciated because of its physical and chemi- as smaller amounts of linoleic, with arachidic, Durán-de-Bazúa MC, Mango seed uses: thermal cal characteristics. behenic, lignoceric and linolenic acids, behaviour of mango seed almond fat and its Some Mexican scientists envaluated among others. Calorimetric analysis showed mixtures with cocoa butter, Bioresource the physicochemical characterization, in- that MAF crystallizes between 14.6 and Technol, 2004, 92(1), 71-78].
Vol 4(6) November-December 2005 511 Oil\Fats
Linseed oil may improve nutritional quality of the lipid fraction of dry-fermented sausages
As meat and meat products, are lipid fraction of dry-fermented sausages was Hexanal and nonanal showed the highest some of the most important sources of dietary achieved by a substitution of one quarter of values in linseed oil-containing products. fat, modification of the lipid profile of such the amount of pork backfat present in Addition of antioxidants avoided the products, by enhancing n-3 polyunsaturated traditional formulations by an emulsion in formation of decadienals and other fatty acids, can help to improve the nutritional which linseed oil was included. This aldehydes from lipid oxidation. quality of the occidental diet. Research has improvement was particularly noticeable In conclusion, the addition of linseed been done on animals by feeding diets rich when 100mg/kg of butylhydroxytoluene and oil to the formulation of dry-fermented in polyunsaturated acids, basically n-3. 100mg/kg of butylhydroxyanisole were sausages has a relevant influence on the Linseed (Linum usitatissimum Linn.) added. P/S ratio increased from 0.4 in the nutritional quality of the products, without has been widely used for this purpose, both control sausages to 0.6 in the batch with substantially modifying the flavour and as seeds and as oil. Researchers of Spain 3.3% linseed oil and to 0.7 in the batch with oxidation status of the ready-to-eat products. carried out studies to evaluate the lipid linseed (3.3%) and antioxidants. The n-6/ However, more research is needed to modifications undergone in dry-fermented n-3 ratio decreased from 14.1 in control substantiate evolution of the lipid oxidation sausages, during the ripening process, when products to 1.7-2.1 in modified products as process during the shelf life of linseed- pre-emulsified linseed oil was used in the a consequence of the α-linolenic acid containing sausages [Ansorena D and Astiasaran formulation, mainly focussing attention on increment. No oxidation problems were I, The use of linseed oil improves nutritional quality the changes in the P/S and n-6/n-3 ratios. detected during the ripening process, with of the lipid fraction of dry-fermented sausages, Improvement of the nutritional quality of the TBA values always lower than 0.23 ppm. Food Chem, 2004, 87(1), 69-74].
Physico-chemical properties of Papaya seed oil Papaya is important for its fruit and Neutrase®0.8L (Neutral protease), (1.39%). The predominant fatty acid in the it is also grown for papain production. The Celluclast®1.5L FG (Cellulase) and oil was oleic acid (72-78%), with some seeds of papaya fruits are generally Pectinex®Ultra SP-L (Pectinase). The melting palmitic (12-14%), stearic (4-5%) and discarded. However, in order to make a more point of the oil was 9.7-10.5ºC and showed linoleic (2.5-3.5%) acids with no significant efficient use of papaya, it is worth investigating that there was no significant difference difference in fatty acid compositions between the use of the seeds as a source of oil. (P>0.05) between the oil obtained from oil extracted using solvent and enzymes. The Currently, two main processes for the enzyme and solvent extractions. Generally, main triacylglycerols (TAGs) were sn- extraction of oil from seeds are of industrial the colour of the oil was reddish yellow. glycerol-oleate-oleate-oleate (OOO) (43.5- importance: the hydraulic process and Solvent-extracted oil tended to have more 45.5%) and 1-palmitoyl-dioleoyl glycerol further purification and the chemical process yellow and red colour (24Y+4.0R) (POO)+stearoyl-oleoyl-linoleoyl glycerol using organic solvents. The scientists at compared to enzyme-extracted oil (SOL) (29.5-30.5%). Thus, papaya seed oil Malaysia evaluated the physico-chemical (20Y+3.0R). The iodine and the has the potential to became a new source of properties of seed oil from Carica papaya saponification values of the solvent-extracted high-oleic oil. However, toxicological studies Linn. to determine and to compare the oil were found to be 66.0 and 154.7, need to be carried out before considering physico-chemical properties and the quality respectively, while those of the enzyme for food applications [Puangsri T, Abdulkarim of oil extracted from papaya seeds using extracted oil were 66.2-69.3 and 154.2- SM and Ghazali HM, Properties of Carica different enzymes with that of oil extracted 161.7, respectively. The unsaponifiable papaya L. (Papaya) seed oil following extractions using solvents. matter of the oil extracted using different using solvent and aqueous enzymatic methods, J Four commercial enzymes were enzymes ranged between 2.07 and 2.90% Food Lipids, 2005, 12(1), 62-76]. used for the enzymatic extraction, namely, and were significantly different (P<0.05) Termamyl 120L, Type L (α-Amylase), from that of the solvent-extracted oil
512 Natural Product Radiance