Process optimization for manufacturing of orange beverage through using hydrolyzed milk permeate

Permeate is the by-product of ultrafiltration operation in a kind of cheese-making process that leakage from membrane in a liquid form and mainly it contains 4.5-4.8 % lactose and 0.44-0.47 % mineral salts.The problem with permeate is its disposal.This study aims to use permeate and its lactose as a part of sugar and utilize useful compounds of permeate in formulation of orange beverage. For this purpose heated and non-heated permeate samples incubated and hydrolyzed by using of B-glycosidase enzyme in three thermal range (35,40,45) Celsius degree and three time intervals (60,150,240) minutes and three enzyme range (0,0.1,0.2) percent. Degree of hydrolysis was analyzed by using the Milkoscan instrument. The results showed that the heated sample with 0.1% enzyme content during 150 minutes and in 40°C gives the best results. In the next stage of study, orange drink was prepared with a mixture of sugar (10-40) percent and hydrolyzed permeate (10-40) percent in a definite brix. After pasteurization and packaging in bottles, the samples were kept refrigerated for 8 weeks. During storage times, physico-chemical analyses were performed on samplesfor pH, sugar content, density,TS,vitamin C and sensory evaluation. Statistical analysis results showed pH and sugar content increment and density, TS and vitamin C decrement trendover time.The optimum pointwas obtainedin using of35% permeate and storage time of 41 days in which the relevant amount of formalin index,vitamin c and sensory evaluation were the favorable amount. General evaluation of beverages, stored at refrigerator temperature, was desirableby the end of the eighth week. According to the results obtained from the study the orange drink producing with the permeate percent above was evaluated favorable.