S S Zamal
Assist. Engineer (S&W)
BADC, Gazipur
M B Uddin
Prof. and Dean,
Faculty of Agril. Engg., BAU, Mymensingh
M S Huda
Scientific Officer
Farm Division, BARI, Gazipur-1701
A Hannan
Scientific Officer
Farm Division, BARI, Gazipur-1701
R U Choudhury
Associate Professor
PGRC, BARI, Gazipur-1701
Soymilk, Shelf life of soymilk, Sensory eveluation
Department of Food Technology and Rural Industries, Bangladesh Agricultural University, Mymensingh, Bangladesh
Quality and Nutrition
Performance
The study was conducted in the laboratory of the Department of Food Technology and Rural Industries, Bangladesh Agricultural University, Mymensingh, Bangladesh during July to December, 2005. The soybean variety (Sohag) used in the study was collected from Bangladesh Seed Foundation, Bangladesh Agricultural University. Shelf-life studies Conducted at Room Temperature (°C) and Refrigerated Temperature (°C). Sensory evaluation was conducted to evaluate the colour, flavour, taste and overall acceptability. Soymilk was prepared from the big size, thin hull and not more than one year old, straw yellow or yellowish green varieties of soybean free from immature, field damaged and black soybeans. Using grain cleaners, the foreign materials was removed. Heavy aspiration removed loose hulls, weed seeds and other light foreign matter. The clean and fresh soybean seeds were then soaked in water (water: soybean = 4:1) at room temperature for overnight. The soaked soybeans were heated with water for 20 min at 60°C (water containing 0.5% sodium bicarbonate (NaHCO3) to remove the bitterness and anti-nutritional factors (trypsin inhibitor). Soaked soybean’s husk were removed by pressing between thumbs and cleaned with continuous flow of fresh water. The clean dehulled soybeans were blended with water (2L/500g) through a warning blender for 2 min at high speed. The homogenized mash was filtered through a muslin cloth by squeezing to obtain soymilk. Each sample of soymilk was treated with three preservatives like KMS, sodium-benzoate and potassium sorbate. The preservatives were used singly or as a mixture of the above three preservatives. The treatments were S1 = Without preservatives (control), S2 = With preservative KMS, S3 = With preservative sodium benzoate, S4 = With preservative potassium sorbate, S5 = Mixed preservative of KMS, sodium benzoate, potassium sorbate. solution. One ml sample stock solution was further dilated with 9 ml phosphate buffer saline (PBS) in a taste tube. From this diluted stock solution, a series of subsequent 10 fold dilution ranging from 10-1 to 10-6 was prepared. The media for total plate count of micro-organism was prepared. Composition of 1 litre nutrient Agar was as 5 g Tryptone (peptone), 2.5 g Yeast extracts, 1.0 g Glucose, 15.0 g Agar, 1000 ml Distilled water and 5.0 g NaCl.The ingredients tryptone, yeast extract, glucose and agar were weighed. The ingredients were dissolved in 1000 ml of distilled water. The mixture was boiled for dissolving completely and was sterilized in an autoclave at 121°C temperature (15 PSIG pressure for 15 min). the media was then cooled at 40°C and distributed to Petri dishes.The prepared soy milk were packed in ten aluminium foil as control and by adding the preservatives as per treatments. Then stored in a refrigerator and at room temperature. The changes of colour, flavour, texture and taste of soymilk sample were observed at different intervals at room temperature (28-35°C) and refrigerated (5±1°C) storage condition in aluminium foil package. Storage samples were observed in every 12 hours for colour, flavour, texture and taste and visual fungal growth. The sensory evaluation of the samples were conducted for colour, flavour, taste and overall acceptability by a panel of 10 panelists. The taste panelists were asked to rate the sample on a 9 point hedonic scale for colour, flavour, taste and overall acceptability with the ratings of: 9 = like extremely, 8 = like very much, 7 = like moderately, 6 = like slightly, 5 = neither like nor dislike, 4 = dislike slightly, 3 = dislike moderately, 2 = dislike very much, 1 = dislike extremely. The results were evaluated by Analysis of Variance and Duncan’s New Multiple Range Test (DMRT) procedures of the MSTAT system.
Eco-friendly Agril. J. 4(01):520-523, 2011 (January)
Journal