The Interdisciplinary Journal of Applied and Medical Sciences (2014) Vol 1, Issue 1: 4-10

Original Research Article Quality analysis of savory bread (buns) with respect to moisture content Naveena K V A*

Abstract

Introduction: Various studies have been conducted to determine the moisture content of white breads. But, analysis and reported studies of moisture content and water absorption power of savory bread rolls are limited. This investigation aims to assist bread roll manufacturers in understanding the average moisture content in savory breads in an Indian atmosphere. Materials and Method: Six types of buns have been considered in this investigation. These were: Cream bun, Tea bun, Sweet bun, Cherry bun, Masala bun, Burger bun. The research has been carried out at an established, fully mechanized bakery in South India. Water content, or moisture content, is a measurement of the total water contained in a food. The moisture content of various kinds of savory breads, before and after proving, and, after baking was determined. Result: The moisture content significantly reduced during the resting phase, which is, proving time. This shows that buns behave differently than breads. The proving environment, with a maintained relative humidity, does not affect the reduction in moisture content. Conclusion: The final moisture content of the full-baked bread depends on the temperature and time applied for full-baking. Only the moisture content and the weight of the buns with respect to the water and flour are reported here. It is also understood that proving of buns has reduced the moisture content.

Key words: Savory bread, buns, moisture content, WAP Introduction Buns may have added fruit (any dried Savory breads are mostly round in fruit including sultanas, currants, cherries or shape, most commonly hand-sized or mixed fruit peel), spices, essences, egg, milk smaller, dome-shaped, with a flat bottom, but powder or butter. Fruit is added after mixing they may come in different shapes. These to avoid crushing it and spoiling the appearance of the product. The three rolls, commonly called ‘buns’ are commercially bought and are consumed as it essential ingredients of dough are flour, air is or as an accompaniment. A bun is and water. The water is divided between normally made from dough that has been bound water, a component of dough 'enriched' with sugar and butter and even structure, and free water, responsible for sometimes egg. Without any of these the dough fluidity. The amount of water added dough remains to be 'bread dough' rather will depend upon the moisture content and than 'bun dough' and the resultant product the physicochemical properties of the flour. will be called a roll, rather than a bun. Dough-water content increases with increase in protein content and, the amount of

A Department of Food Processing, Loyola College, Chennai * Corresponding mail: [email protected] 4 tijams ______Naveena : Moisture analysis of Buns damaged starch. Dough does not form at on the bread. Moulds get killed during the water contents below 35% and are baking process but spores and moulds excessively runny and difficult to handle at present in the air of the bakery, are the cause water contents above 50%. [1] that the bread gets polluted after it comes Around 40% of the standard bread after the oven. Although strict application of dough is comprised by water and over 35% good manufacturing practices with regards to is seen in baked bread. [2] By practice the re-infection can and will limit mould growth, a 100 % mould-free environment is difficult water absorption of wheat flour dough is [9] influenced by the protein content and quality to achieve. and by the extent to which the starch is It has been reported, however, that it is [3] damaged mechanically. the water activity (aw) rather than water content that governs microbial spoilage of The consistency of bread dough is a [10] function of its moisture content. Hydration or foods. Development of many baked water content cannot be considered alone, products involves maximizing the moisture but relatively in relation to the nature of flour content to produce the best possible eating in a recipe. Different flours have different qualities while minimizing aw. Lowering aw increases product stability in terms of rates of water absorption. This is largely due [11] to the character or kind of protein present in susceptibility to microbial growth. the flour. [4] Water activity values are useful when determining the safety or shelf stability of a Water plays an important role in the product. [8] major transformation that take place during baking. These changes include starch This study was intended to establish gelatinization, protein denaturation, yeast the variation of moisture content in buns and enzyme inactivation, flavor and colour after proving (resting phase) and also after formation. [5] baking. The difference in weight, before and after baking, exhibited by the product and, its It has been indicated that water acts relation to the moisture content has also been as plasticizer in the bread. Therefore, simultaneously studied. decrease in the moisture content favors the formation of hydrogen bonds among the Materials and Methods starch polymers or between the starch and Process of Bun making [6] proteins, resulting in greater hardness. The bun making process can be Water content and its distribution also categorized as follows: govern the shelf life of bread, which is Sieving Weighing Mixing influenced by incidence of microbial Dividing Proving Baking damage, softness of the crumb, crispness of Cooling Packing the crust, crumb hardening, crumbliness, and many other changes associated with overall The flour is thoroughly sieved which staling and lowered consumer acceptance. [7] helps its aeration, remove any impurities and Water content values are useful when: coarse particles and also makes the flour homogeneous. Different ingredients are . establishing the dry weight of a food weighed precisely as per the formulation. or ingredient These ingredients include sugar, salt, . determining yield oxidizing agents and yeast. The sequence of . confirming the end point of a drying [8] addition of ingredients also affects the dough process characteristics. Generally the shortening and The relatively high moisture content of salt are added after the clean up stage. bread encourages the development of mould

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Mixing of flour and ingredients consecutive weighing was less than 1mg. involves hydration and blending, dough The lowest reading was then recorded. development and, dough breakdown. The Water content, or moisture content, is dough is mixed up to the minimum mobility a measurement of the total water contained point which serves to produce bread of in a food. [8] It is usually expressed as a superior quality. percentage of the total weight: The molded dough pieces are then Mw (wet basis) = (w-d/w) x 100 placed in bun pans or tins for proving. Proving takes about 55-65 minutes and is Mw = moisture content on a percent basis carried out at 30-35°C and at 85% relative w = wet weight humidity. During proving the dough d = dry weight increases remarkably in volume. A high Determination of water activity (aw) humid condition is mandatory to minimize weight loss. The dough is then subjected to Water activity is a measurement of heat in a baking oven maintained at a general the availability of water for biological temperature range of 230-240°C for 10 min. reactions. It determines the ability of micro- The internal temperature of the dough should organisms to grow. If water activity reach to about 95°C to ensure that the decreases, micro-organisms with the ability product structure is fully set. After baking, to grow will also decrease. the buns are cooled prior to packing and Water activity (aw) is expressed as the ratio labeling. The relative humidity also is of the vapor pressure in a food (P) to the maintained at 65% to prevent excessive vapor pressure of pure water (P0). It moisture evaporation from the surface. envisages whether water is expected to move from the food product into the cells of micro- Six types of buns have been considered [8] in this investigation. These are: organisms that may be present. 1. Cream bun aw= P/P0 2. Tea bun Determination of Water Absorption Power 3. Sweet bun (WAP) 4. Cherry bun 5. Masala bun Strong flour with higher gluten 6. Burger bun content has a higher water absorption capacity (WAP) which in turns results in The commercial bread flour used in the higher yield of bread. study was also analyzed for its protein content, ash%, gluten content, water 25 g of flour sample was taken in a absorption power and alcoholic acidity value. china dish. Water was added in small A high value for alcoholic acidity of flour is portions to the dish from a burette and mixed an index of the extent of deterioration the until well kneaded dough of medium flour has undergone during storage. consistency is obtained. The volume of water utilized was recorded. Determination of moisture content: WAP was calculated by placing the The moisture content was determined following formula: at different stages- the dough, after proving and after baking. Weighed amount of WAP (%) = (Volume of water required samples were dried in an oven at 105°C +/- (ml)/Weight of sample taken) * 100 1°C for 30 minutes, cooled in a desiccator Results and Discussion and weighed again. The whole process was continued until the difference between two The baking time for each type of bun was 237°C. The commercial bread flour used

6 tijams ______Naveena : Moisture analysis of Buns in this study contained 11% protein, 0.55% By lowering water activity, food can Ash on a 13% moisture level and 10.3% be made safe to store. Moulds have gluten. The water absorption power (WAP) minimum water activities for growth and was determined by an experienced toxin production. Most moulds require a experimental baker and found to be 62%. higher water activity than the minimum Alcoholic acidity value was estimated by requirement for growth to titration against 0.05N standard sodium produce mycotoxins. The proving hydroxide solution and was found to be environment, with a maintained relative 0.1%. It has been noted that a proving time humidity, does not affect the reduction in of 5 minutes was sufficient for the masala moisture content. The expected result was in (spicy) variety of buns as compared to the the reverse as reported for bread loaves. other buns that have relatively higher amount It has also been reported that the of sugar in them. crispiness of the bread crust is determined by the water content and not by the local water Table I summarizes the proving time activity of the bread. [13] and baking time for each product. Proving time for the breads having higher content of Table III summarizes the average sugar was almost an hour longer than that for weight of the buns at different stages of the less and minimal sweet buns. processing. We can see that the weight of the buns after baking has an appreciable Table II gives a review of the decrease while after cooling we find a slight moisture content in the different types of increase in weight. This may be attributed to savory breads. From the figure I we can the absorption of moisture from the understand that the moisture content environment in the cooling chamber. It is significantly reduced during the resting also noted from the graph shown in figure II phase viz, proving time. This shows that that there is no direct relation between the buns behave differently than breads as moisture content and end weight of described in the study conducted by the product once the buns have [12] Coppock on white bread loaf. completed the baking procedure. Tables and Figures

Table I Comparison of proving and baking time

Product Proving Time Baking Time

Buns having Cream Bun 2 hr 15 min 10 min high sugar content Sweet Bun 2 hr 15 min 10 min

(9-11%) Cherry Bun 2 hr 10 min

Buns having Tea Bun 1 hr 30 min 10 min lower/minimal sugar content Burger Bun 1 hr 15 min 10 min (5-7%) Masala Bun 5 min 12 min

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Table II Moisture content at different stages of production

Product Dough Moisture (%) After Proving Moisture (%) After Baking Moisture (%)

Cream Bun 58.7 34.45 34.86

Tea Bun 59.1 34.97 36.68

Sweet Bun 60.12 34.26 40.75

Cherry Bun 56.92 36.19 43.33

Masala Bun 55.2 38.49 41.8

Burger Bun 62.7 41.92 43.2

Table III Weight (in grams) of the sampled product

Product Dividing weight Weight after Baking Packing weight

Cream Bun 0.56 0.3 0.43

Tea Bun 0.41 0.37 0.18

Sweet Bun 0.6 0.54 0.53

Cherry Bun 0.46 0.41 0.19

Masala Bun 0.34 0.27 0.11

Burger Bun 0.31 0.13 0.12

Figure I Graphical comparison of moisture content

70 60 50

40 dough moisture % 30 moisture % after proving 20 moisture% after baking 10 0 cream tea bun sweet cherry masala burger bun bun bun bun bun

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Figure II Graphical illustration of weight (in grams) at different processing stages

0.7 0.6 0.5 0.4 0.3 dividing weight 0.2 weight after baking 0.1 packing weight 0 cream tea bun sweet bun cherry bun masala bun burger bun bun

Conclusion formation of hydrogen bonds among the The final moisture content of the full- starch polymers or between the starch and baked bread depends on the temperature and proteins, resulting in greater hardness. [6] time applied for full-baking, which has an Water content measurement plays an important impact on the properties of the essential role in food technology and it is [14] bread. subject to a fast growing interest due to Breads and cakes are normally sold increasing requirements in product quality by small-scale bakers within a day of baking control. [16] Only the moisture content and to retain the fresh baked flavour and odour the weight of the buns with respect to the and the correct texture. Staling takes place water and flour are reported here. It can be rapidly at tropical temperatures and leads to understood that proving of buns has reduced a toughening of the crumb and, in some the moisture content and not the baking. This bread, softening of the crust. The changes phenomenon needs to be studied further. happen in both humid and dry climates but An extensive study would be required additionally there may be drying out of some to determine the effects of the individual products in dry climates. Because of the ingredients and their interactions on the short shelf-life, packaging is mainly used to moisture content and aw in savory breads. keep these products clean and it is not used Further studies need to define [15] as a barrier to moisture or air. whether the weight of breads is not

It has been indicated that water acts particularly affected by the local moisture as plasticizer in the bread. Therefore, levels. decrease in the moisture content favors the

References 1. Gil, M.J., Callejo, M. J., and Rodríguez, 2. Available at G. Effect of water content and storage http://www.classofoods.com/page1_2.ht time on white pan bread quality: ml. Accessed on 11th June 2014 instrumental evaluation. Zeitschrift für 3. Bushuk W, Hlynka I. Water as a Lebensmitteluntersuchung und - constituent of flour, dough, and bread. Forschung A. 205 (4). p. 268-273 Baker’s Dig1964. p. 38-43

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4. Baker's Percentages - Description, 11. Burrington, J. Kimberly. 1998, Examples & Spreadsheet Prolonging Bakery Product Life - http://www.theartisan.net/BPercent.htm. Design Elements July 01, 1998 – Article Accessed on 11th June 2014 12. Coppock J B M, Knight R A, Vaughan 5. Czuchajowska Z, Pomeranz Y, Jeffers H Margaret C. The Moisture Content of C. Water activity and Moisture Content White Bread. International Journal of of Dough and Bread. Cereal Chem1989. Food Sciences and Nutrition (1958). p. 128-132 12(2): 63-66 6. Schiraldi A, Fessas D. Mechanism of 13. Nieuwenhuijzen N H, Primo-Martin C, Staling: An Overview. In: "Bread et al. Water content or water activity: Staling", CRC Press, Boca Raton 2011. What rules crispy behavior in bread p. 1-17. crust. Journal of Agricultural and Food 7. Pomeranz Y. Moisture content of whole Chemistry (2008). 56: 6432-6438 bread and bread crumb. Nature (1959). 14. Majzoobi M, Farahnaky A, Agah Sh. 183(4668): 1122 Properties and Shelf-life of Part-and 8. Available at Full-baked Flat Bread (Barbari) at http://www.gov.mb.ca/agriculture/food- Ambient and Frozen Storage. J. Agr. safety/at-the-food-processor/water- Sci. Tech. (2013); 13: 1077-1090 content-water-activity.html. Accessed on 15. Fellows, Peter. Axtell, Barrie. Extension 11th June 2014 of shelf-life. Appropriate Food 9. Available at Packaging (Tool).Chapter 2.3, Tool http://www.classofoods.com/page3_5.ht Publications ml. Accessed on 11th June 2014 16. Liu Zhi, Moller Flemming. Bread water 10. Beuchat L R. Microbial stability as content measurement based on affected by water activity. Cereal Foods hyperspectral imaging. IMM-Technical World; (1981). 26: p. 345 Report 2011; No. 15:93-98

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