بهينه سازي شرايط توليد ماندگاري و كيفيت نوشيدني ميوه اي آب و پنير

Optimization of production, storage and quality of whey-based fruit juice beverage

The objectives of this study were: 1- to screen out the suitable fruit juice. 2- tO evaluate the optimum conditions for storage and quality, of a whey-based fruit beverage. This investigation was carried out in 2 phases, in the first phase 27different formulations of whey- based beverage were prepared using 3 types of concentrated fruit juice (orange, grape and sour cherry) at 3 levels (3,4 and %5) and different amounts of sugar (5,10 and %15). Taste, aroma, appearance and total acceptance of all prepared samples were evaluated by trained panelists using a 7 point hedonic scale. The amount of concentrated fruit juice, sugar amount and interaction of them(p<0.01) as well as interaction of fruit juice concentration and sugar amount (p<0.05) on total acceptability of samples were significant. Based on obtained results of the first phase, it was found that a whey-based orange beverage was the most suitable and acceptable one. In the second phase a whey-based orange drink was produced by heating under 2 conditions:80°C for 5 minutes and 90°C for 10 minutes. Samples were packed in flexible packaging and were stored at refrigerator as well as ambient temperature. Beverages were taken in 2weeks intervals and were evaluated chemically and organoleptically. Data obtained from both phases were analyzed using a complete randomized block design. The effect of storage time and temperature and also the interaction of them (p<0.01)on taste, appearance and total acceptance of beverages was significant on while only the effect of storage time (p<0.01)was significant on the aroma of samples. The influence of storage time on the pH of experimental samples was also evaluated statistically using t-test. The result sbowed that there was a significant difference(p<0.05) in the pH of samples stored at refrigerator and ambient temperature.