Development of a User Friendly Bread Improver For Bakery Industry. By S.B Navaratne

INTRODUCTION Bread is an inalienable product from the modern dynamic society. Which has already been integrated with the consumers in demographic as well as geographic market segments alike. Because, this product has been enriched with an attractive sensory profile, ready to eat phenomenon and time easing capacity of the busy life style. Hence, acceptance of this product is broad spectrum with respect to the need hierarchy.

Thus, stiff competition has been emerged among the bakers and they attempt to maintain the competitive edge in terms of quality. Therefore, bread improvers can play a crucial role in the arena of quality.

Scope of the Study To preserve as much fungal alpha amylase as possible in the bread improver, because wheat flour lack of this enzyme and also this enzyme is heat tolerable up to 600C. Where as, Alpha amylase is the enzyme, which merely initiate the leavening process of yeast leaven bakery products.

OBJECTIVES OF THE STUDY Development of a user friendly bread improver for bakery industry. Preservation of enzyme(α amylase) secreted by yeast with an appropriate drying techniques. Development of a methodology to extract alpha amylases as maximum as possible. Application of developed bread improver in commercial scale bread manufacturing process.

MATERIALS AND METHOD Materials. Cleaned wheat flour, Yeast, Sugar, Ice cubes, Distilled water, pH meter, Electronic balance, measuring cylinder, Cooling with de-humidifying dryer and Mechanical dryer

METHODOLOGY Two factor factorial design with three variables at two levels were taken into account. Variables i. Amount of Yeast(leavening agent) 1% and 3%. ii. Period of fermentation – 3 hours and 6 hours. iii. Method of drying – Cooling with dehumidifying and sensible heating at constant humidity ratio drying processes.

2Kg of cleaned wheat flour was taken, 3% sugar and 60% distilled water were incorporated and mix well in order to form dough of suitable consistency. Prepared dough was subjected for the subsequent trials of the experiment.

Experimental design 2Kg dough a01% Yeast a1 3% Yeast b03hrs ferme b1 6 hrs fermen b0 3 hrs fer b16 hrs fer C0 C with D C1 SH C0Cwith D C1SH C0CwithD C1SH C0Cwith D C1SH 80C 1000C 80C 1000C 80C 1000C 80C 1000C All treatments were chilled after completion of fermentation process. Eight treatment combinations were prepared. Moisture content of the treatments was maintained at 8-10% after drying.

8 treatment combinations were evaluated by incorporation of 2% of the treatment to normal bread dough and monitored i Time taken to reach optimum leavening index 2.0 and ii Leavening efficiency

Selection of best treatments L. Index = Increment volume of the dough Initial volume L. efficiency= L.ti me (without treat- with treat) to reach Lindex .02*100 L.time to reach L. index 2.0 (Without treatment) Best treatments were selected in terms of leavening index and leavening efficiency. Thereafter, best two treatments out of 8 were subjected for commercial scale bread manufacturing process and bulk density and pH value of which were compared as against same of normal bread.

Results and discussion Leavening efficiency of the treatments Treatment Mean value of 3 replicates Mean value Total Just after 1 month after 2 months after 3 months after a0b0c0 a1b0c0 a0b1c0 a1b1c0 a0b0c1 a1b0c1 a0b1c1 a1b1c1 35 28 48 27 13 16 34 47 26 12 15 34.5 27.2 47.5 27.5 26.5 12.5 15.5 138 109 190 110 106 50 107 62 872

Best treatment is 1% yeast, 6 hours fermentation time and cooling with dehumidifying drying process. The results were analyzed statistically in order to determine whether there is a significant difference between the treatments

ANOVA Table Source Sum of square df Mean square F value Between treatment Error Total 3666.5 388.6 3284 7 24 31 523.6 16.2 105.9 34.01 Table F value F724 =2.42 DMR values revealed that the best treatment was 1% yeast, 6 hrs fermentation time and cooling with dehumidifying drying process, as difference between mean value of a0b1c0 treatment and all other treatments remained greater than the DMR value.

Mean leavening time of 3 replicates (minutes) and X±SD LEAVENEING TIME Mean leavening time of 3 replicates (minutes) and X±SD Control a0b0c0 a1b0c0 a0b1c0 a1b1c0 a0b0c1 a1b0c1 a0b1c1 a1b1c1 180 115 130 90 127 140 166 135 156 180±.2 115±.1 130±.1 90±.1 127±.1 140±.2 166±.2 135±.2 156±.2 Best treatment is 1% yeast, 6 hours leavening time and cooling with dehumidifying drying process. Because, it takes least leavening time. The next best treatment is 1% yeast, 3 hours leavening time and cooling with dehumidifying drying process.

The best two treatments were compared along with ordinary bread manufacturing process in terms of leavening index.

Leavening index (Mean value of three replicates) Leavening time (hrs) Leavening index (Mean value of three replicates) a0b1c0 a0b0c0 control 0.5 1.0 1.5 2.0 2.5 3.0 0.7 1.6 0.6 0.3 1.2 1.8 Best treatment is 1% yeast, 6 hours fermentation and cooling with dehumidifying drying process. Quality of bread were compared in terms of pH value and bulk density of bread crumb.

Bulk density and pH value of best two treatments along with common bread. Physical parameters (Mean value of 3 replicates) a0b1c0 a0b0c0 Control Regulatory requirements pH value X±SD Bulk density 5.7 5.7±0.2 0.10 0.10±0.01 5.5 5.5±0.18 0.12 0.12±0.01 5.4 5.4±0.21 0.125 0.125±0.02 5.3-6.0 pH of all breads are remained within the regulatory requirement. Bulk density of treatment a0b1c0 is less than the other two treatments.

Conclusion Yeast extract particularly alpha amylase can use as a bread improver in order to accelerate leavening process of yeast leavened bakery products as well as improvement of bread crumb structure.

References Nawaratne S.B 2004, Sri Lanka Association for the Advancement of science “Development of a quantified relationship between manufacturing techniques and regulatory requirements. Potter, N.N. and Hotchkiss, J.H. 1986, Cereal grains, Legumes and Oil seeds in Food science, Chapman and Hall, Newyork, Pp 381-404. Sri Lanka Standards 141: 1992 Specification for White bread, Sri Lankan standards institution. Stanley P. Cauvain and Linda. S. Young 1999, Technology of Bread making. A Chapman & Hall Food Science Book, Aspean Publishers, Inc, Gaithersburg, Maryland. Swaminathan, M. 1988. Hand book of Food Science and Experimental Foods. The Bangalore Printing Co. Ltd; Bangalore. 560018 pp 107.

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