Effect of processing and soybean cultivar on natto quality using response surface methodology.

In an attempt to commercialize the traditional technology of fermenting soybean into natto on laboratory scale using three locally available soybean varieties, that is, white, black, and brown, response surface methodology (RSM) was used to determine the optimum combination of two factors, that is, the effect of steaming time (20-50 min) and fermentation time (12-48 hr). Thirteen samples from each variety were formulated which were packed in low-density polyethylene for LDPE using the isolated culture from the natto sample and incubated at 37°C, and the sensory data were analyzed by using Design Expert (RSM). All the responses (taste, hardness, thread/stickiness, and overall acceptance) were significantly (p < 0.05) affected by the two variables except appearance for all three varieties of natto prepared. The optimum combinations of steaming time (min) and fermentation time (hr) were found for white soybean natto (33.4 min and 34.5 hr), for black soybean natto (34.7 min and 30.9 hr), and for brown soybean natto (33.2 min and 34.9 hr), respectively. The proximate composition of soybean and best three formulated natto obtained after sensory evaluation from 13 samples of each variety were studied, that is, moisture, crude protein, pH, calcium, and iron on dry basis found to have increased, whereas carbohydrate and crude fiber found to have slightly decreased, but crude fat and ash found to be almost equal on three varieties than the raw soybean used. Microbiologically, the product was hygienic and safe as coliform and salmonella were not detected.

Extraction and process optimization of bael fruit pectin.

Pectin was extracted at temperature of 100 and 120°C with two different pH conditions each, pH 1.5 and pH 2 along with different extraction ratios, ER1:1, 1:1.5 and 1:2 respectively. Data obtained were analyzed statistically using ANOVA (no blocking) at 5% level of significance, which showed that there was significant difference (p < 0.05) between the pectin extracted at 100°C, pH 1.5 and extraction ratios of 1:1, 1:1.5, and 1:2, respectively, whereas there was not any significant difference between extraction at 120°C, pH 1.5 and extraction ratios of 1:1, 1:1.5, and 1:2 respectively. Also, there was no any significant difference between pectin extracted at 100°C, pH 2, extraction ratios 1:1, 1:1.5, and 1:2 and also at 120°C, pH 2, 1:1, 1:1.5, and 1:2 respectively. Best yield of pectin was found at temperature 120°C, pH 1.5 and ER 1:1.5.

Preservative effects of some selected spice oleoresins to stabilize the sunflower oil in comparison to tertiary butylhydroquinone.

DPPH (1, 1-Diphenyl-2-Picrylhydrazyl) radical scavenging activity was performed to find out the antioxidant activity (AA) of all the antioxidants used at a concentration of 5, 10, and 15 µl/ml. Effect of spice oleoresins (clove, black pepper, and ginger) (200 ppm) and TBHQ (200 ppm) were incorporated in stabilizing refined, bleached, and deodorized (RBD) sunflower oil heating at frying temperature (170°C) and during accelerated oxidation storage (70°C) was studied in comparison to Tert-Butylhydroquinone (TBHQ). Antioxidant activity (AA) was found to be in the order TBHQ > clove > ginger > pepper at a concentration of 5; 10; 15 µl/ml. A direct correlation was found between AA and the effectiveness of oleoresins and TBHQ in controlling AV and PV of the sunflower oil. During both heating and storage, TBHQ was found most effective to control AV and PV followed by clove, pepper, and ginger.