Zeynab Raftani Amiri; Mohammad Ezazi
Abstract
Introduction: Nowadays, use of by products in formulation of functional foods in order to improve their nutritional value and also avoid environmental pollution in food industry is increasing. Whey, a by product of dairy industry is one of such compounds. The acid whey resulted from concentration of ...
Read More
Introduction: Nowadays, use of by products in formulation of functional foods in order to improve their nutritional value and also avoid environmental pollution in food industry is increasing. Whey, a by product of dairy industry is one of such compounds. The acid whey resulted from concentration of yoghurt, as a by-product, can be applied in whey based fruit beverages due to its minerals and beneficial residual proteins. It represents about 85–95% of the milk volume and contains nutrients, such as lactose as a most content, soluble proteins, lipids, minerals, vitamins, and organic acids. Acid whey has a pH of approximately 4.5 due to the conversion of lactose into lactic acid by lactic acid bacteria during the process of yoghurt production. Lactose is the main ingredient of whey, which comprises 90 percent of whey dry matter. According to FAO, the worldwide production of cheese was estimated to be 19,000 kilo tones (kt) in 2010, thus resulting in approximately 177,000 kt whey as a by product. The annual growth arises to production of approximately 211,000 kt whey in 2020. Therefore, the research for new lucrative whey utilization beside whey protein recovery is an ongoing challenge for the dairy industry. More than 70% of the world’s population suffer from lactose intolerance, which limits consumption of lactose containing dairy products. Lactose intolerant individuals, who consume milk or other dairy products like as acid whey, even at small quantities, facing gastroenterological complications related to the uptake of calcium and certain other nutrients. Thus it is important to reduce the lactose content of mild and dairy by products before using them in new foods formulation. In this study production of low lactose whey by enzyme was investigated. Beta-D-Galactosidases, EC (3.2.1.23), is a hydrolase enzyme that converts lactose into glucose and galactose and increases the sweet taste in products. It is commonly known as lactase, which is one of the most important enzymes in food, dairy and fermentation industries. Mixing of the low lactose whey with fruit compound or concentrates and sweetener agents make delicious and functional new beverage.
Materials and methods: The acid whey resulted from concentration of Greek yoghurt, as a by-product, was applied in whey based fruit beverages. The lactase enzyme (Sapherra FMP) was prepared from Novozyme Company. Pineapple compound prepared by Orana Company from Denmark. The quantity of sugar (Shadianeh) in each sample has been investigated based on the equivalent sweetness recognition by panelists in lactase treated samples in comparison with non treated samples. Premixed sugar and stabilizer in precise amount for each treatment was added to water and agitated in stainless steel agitating mix. After that whey and pineapple compound, and then 1000 ppm enzyme were added to samples and kept at 4 degree Celsius for 3 hours and finally pasteurized. All samples homogenized by 150 bar in 60 degree Celsius. Packaging of samples was done in 250 gram tetra pack container at aseptic condition. The effect of lactase enzyme on sugar quantity and taste improvement of acid whey based beverage produced by 5 percent of pineapple compound, has been investigated by lactase enzyme (0 and 0.1 percent), acid whey (30 and 40 percent), storage temperature (ambient and refrigerator) and time storage (0, 4, 8, 10 and 12 weeks after production) on a factorial experiment in a completely randomized design.
Results and discussion: The results of sensory evaluation in 12 weeks at two different storing temperatures (refrigerator and ambient), showed that addition of lactase enzyme before pasteurization of whey based pineapple flavored compound could kept not only the pH on constant, and reduced the sugar quantity to achieve constant sweetness in all samples, but also improved the sensory specification of beverage, significantly (p
