The Comprihensive Utilization Of Whey From Cheese By-products

Whey is a by-product expelled from cheese production process, including55%nutrition ingredients of milk. Whey is composed of20%milk protein, lactose, mineralsubstance and multivatamins, which has a very high biological value. There is anemerging industry that using whey of cheese by-products to develop a high value-addedproducts-----whey cheese. Dairy industry of developed countries in the world of cheesevarieties have more than400species, while only20kinds of cheese products in ourcountry. Therefore, the whey cheese market in our country is potential and tremendous.This experiment used Mozzarella Cheese whey as a raw material, researching themethod to measure the content and molecular weight of whey protein. Temperature,pressure, and pH condition was studied in the influence of ultrafiltration concentrationprocess, comparing with flash evaporation technology, to determine the best enrichmentprocess of whey. Adding fish protein powder to strengthen the whey cheese quality,testing products digestion rate and recovery rate. Analysing the cheese index of thehardness, chewiness, conglutination and softy with for texture.The research mainly include the following several contents:(1) Mozzarella Cheese whey of various nourishment composition testing resultsare as follows: spectrophotometry to measure total protein content was0.67%(massfraction), coomassie brilliant blue colorimetric method measuring true protein contentwas0.59%, the Rhine-YiNong’s method to measure lactose was4.57%, soxhletextraction method to measure fat content was0.98%, the titration method to measurethe acidity of11.33°T, drying method in normal pressure to measure solid content was7.08%, using a muffle furnace to measure ash content is0.53%. Combining with gelimaging system, SDS-PAGE gel electrophoresis method analyzed the mainly wheyprotein molecular weight:14.14KDa,19.74KDa,23.94KDa,31.73KDa,55.72KDa,82.73KDa, and analyzed the two important protein content of whey: alpha lactalbuminaccounted for27.19%of the total whey protein content, beta globulin accounted for38.27%of the total protein content.(2)Using6KDa of molecular weight to concentrate liquid whey by hollow fiberultrafiltration membrane, membrane separating condition identified as: pH value of5.5~5.5, membrane operating pressure of0.1MPa, concentrated temperature of25℃;Concentrated protein content was3.53%, fat0.09%, lactose content3.27%, dry matter7.50%.(3)With multistage flash evaporation concentrating the whey, and the best processconditions as follows: evaporation temperature of65℃, the feed flowing rate of70mL/min, vacuum pressure of0.085MPa.Concentrated protein content was1.93%, fatcontent was2.01%, lactose content was12.87%, ash content was1.2%, solid contentwas17.94%. Through flash evaporation technology could expell a large number ofwater, and concentrated the whey protein, but when compared with ultrafiltrationenrichment technology, flash concentration at protein content in the proportion of totaldry matter was not obvious improved.(4) Discussing the effect on whey cheese quality by adding fish protein powderwith0.4%,0.8%, and1.2%.Compared with the blank control group, adding fish proteinpowder increased the dry matter content of raw materials, and products also increased indry matter content, thus the cheese producting rate increased with the increment of fishprotein powder. Texture analysis showed that adding group were all increased athardness, chewiness, conglutination, and softy. The experimental group of0.4%and0.8%were not increased greatly in hardness and softy, but the growth of1.2%atexperimental data showed that every index of growing rate was great. Digestion rate ofwhey cheese in experimental group of1.2%reached to93.82%. So in order to improvethe quality of the whey cheese, adding1.2%fish protein powder is admissible.