Use copra meal as a partial substitute for wheat flour in fiber-rich biscuits

Biscuits, which are loved by many consumers, often provide a high level of energy because they are rich in sugar, flour, fat and low in fiber. Fiber plays an important role in preventing constipation, cardiovascular diseases and obesity, so the current trend of manufacturers is to create high-fiber biscuit lines. Defatted copra meal (DCM) is a rich source of fiber and is added to biscuits to increase the fiber content of the cake. In this study, defatted copra meal, after being hydrolysed with the enzyme Cellulast1.5L (HDCM), will be used to replace wheat flour with different ratios, from 10% to 40%, in fiber rich biscuit recipe. The hydrolysis of DCM was carried out with an enzyme concentration of 5U/g dry matter, for 30 minutes. The obtained HDCM has a soluble fiber (SDF) content of 7.3% dry matter, an increase of 2.43 times compared to the DCM sample. At the same time, the ratio between insoluble fiber and soluble fiber (IDF/SDF) of HDCM also decreased by 2.64 times compared to this ratio of DCM. The chemical composition, hardness, physical and sensory parameters of biscuits were used to evaluate the effect of hydrolyzed copra meal replacement rate. When increasing the percentage of HDCM from 20-40%, the total fiber content of biscuits increased 1.7- 5.9 times compared with the control sample. The HDCM substitution rates of 20% and 30%, for biscuits with acceptable taste scores of 5.7 and 5.0, respectively, with total fiber content of 9.0 and 15.5%, respectively, are suitable for manufactures fiber-rich biscuits.

TR OPTIMAL CONDITIONS FOR β-MANNANASE PRODUCTION BY BACILLUS CIRCULANS NT 6.7

Optimum medium for mannanase production is very important and producing medium has been shown effective for mannanase production from Bacillus circulans NT 6.7 but expensive. This work aim to find low cost medium and optimum condition for mannanase production from Bacillus circulans NT 6.7. 1.5% concentration of defatted copra meal as carbon source in shake flask resulted in highest growth and enzyme activities of 10.51±0.53 Log CFU/ml and 12.84±4.38 U/ml at 18 hours accordingly. Also, 2% defatted copra meal in fermenter produced highest growth of 7.94±0.41 Log CFU/ml and enzyme activities of 32.07±2.94 U/ml at 15 hours. Using taguchi design, optimal conditions for inoculum, agitation and aeration were 1%, 600 rpm and 0.75 vvm, respectively. Under this optimized condition, the mannanase experimental yield (29.57±4.81U/ml) closely matched the yield predicted by the statistical model (24.15U/ml) with R2 = 0.75. Using mineral salts medium, slightly increased in mannanase product was observed compare to previously used producing medium. Also, the cost of using mineral salts medium (cost per liter) is 27 time lower than the cost of producing medium. Suggesting that, mineral salt medium provides an economically feasible medium for producing mannanase from Bacillus circulans NT 6.7.