Shelf-life study of spray-dried groundnut milk powder

摘要

Shelflife study of spray-dried groundnut milk powder was conducted in metal tin can and aluminum foil package. The observations were recorded at 0th, 1st, 2nd, 4th, 8th, 12th, and 16th week of storage. There was an increasing trend in the values of moisture content (3.69-7.56% w.b. and 3.69-7.08% w.b.), water activity (0.44-0.68 and 0.44-0.64), and free fatty acid (0.48-2.02% and 0.48-1.87%) in aluminum foil package and metal tins can, respectively. Dispersibility of powder varied between 96.10-90.22% and 96.10-91.78% while insolubility index varied between 0.75-3.88 ml and 0.75-3.56 ml in aluminum foil package and metal tin can, respectively. Results indicated that groundnut milk powder can be safely stored in both the packaging materials for 3 months and metal tin can packaging is better than aluminum foil packaging. A significant difference in the values of the above parameters was observed in commercially available milk powder during the same storage period. Practical Applications Groundnut is widely used for oil extraction or consumed as roasted nuts. Considering its wide acceptability and nutritional value, groundnut processing needs more diversification in order to utilize its potential. Groundnut can be used for the preparation of imitation milk for lactose intolerant population of the country. However, groundnut milk has a very limited shelf life (5-7 days under refrigerated condition) and adds to the increased transportation cost of carrying liquid milk from one place to another. The conversion of groundnut milk into powder using spray drying will reduce product perishability as well as storage and transportation costs. Further, the shelf life study of the groundnut milk powder in different packaging material will be useful in determining the safe storage period as well as the type of packaging material to be used for storing the powder considering the quality as well as sensory attributes of the powder during the duration of storage.