Studies On Enzymatic Modification Of Cow Milk Protein And Infant Milk

Cow ed has been used as infan fonnula for its uinversality of source' bodance ofnutrition and the comParability betWen cow miili and hUman ndlk. However, Ther are Stillsome imPortan difornces betWen them, which make the cow milk protein not be easilydigested and absorbed, pat of infants will be caused allerg1c phenomenon by cow milk PrOtein.The dries between hUman ndlk and cow ndlk include f the thee of the Proteincontent Proponion between the tWo kind of milk, there are large amoun of Protein conen ofa s-casem in cow milk, while alInost no a s-casein m hUInan ndlk, 0-lactoglobulin existS incow milk but not in human milk. Through hydrolyZmg the cow milk protein, the Proponion ofcasein to whey protein was adjusted and, at the same trie, a s-casem and 0-1actoglobulinwere modified. rus Product can be used as Inilk raw material for infan formula and befaVorable to infan digestAner compmp and chOos1ng five kinds of safe and abUndan enZymes, the eapenmentdetennined pancreatin as hydrolyzing emp to moop ndlk protein.Usmg single factor exPchmere and taking the vitro digest raho as the index, the eapenmentdetenmned the ophmum temPeratUIe and pH. Then taken the bitterness extent as standard- theoPtimum hydrolyzing hme was detedned. The result ls f under the condition of temperature45t, Wme concentration 0.5%, the oPtimum vitro digest ration was acqUired. WhenhydrOlyzing for was 20 Ininates, the hydIolysate was no bitter.The way to detennine digest ratio in infan vivo is tO simulate infan stomach digest Processin vbo. Three hOurs in vitro could be used tO shmulate 6 hOurs in vivo. Continuously aPpendrennet and pePsin after hydrolyZing l5 ndnutes, 45 ndnutes and 2 hOurs. TCA was used tOdePosit protein. The ratio of solvable protCin to the tOtal protein was the vitro digest ratio.Using vitr exPerimen to simulate the state of curd in infan stomach.. AdustedtemPeratUre 40'C, pH4.0, observed and phoned the flocculahon. The state of human mllk wasmlld, but the curd of cow milk was bulky and snd The state of hydrolysate was evaluated, itwas more lilie hUInan Iinfa.han acid (AA) content was determined by tbIee kinds of human mIIk. ComPartriresearch had been done betWeen human milk and hvdrolvsate. The differences can be used todetennine how to adjust AA conten in hydrolysate more lilie hUman milk,*fl% HJdftg 2002The DH and vitro digest ratio were determined under the optimum condition. In the first 30 minutes, both increase at a high speed, with the proceeding of hydrolyzing, the increase of the reaction speed was imperceptible.The sensor index was assessed, Molecule mass of hydrolysate was measured and stability was mensured, too. All of which were close to human milk.In order to weeken the bad taste and enhance stability of hydrolysate, the experiment mix cow milk and hydrolysate at all kinds of proportion. The result showed that when the ratio of cow milk:hydrolysate is 5:5, the hydrolysate has no ill flavor and has good stability. The mixture can be used as material of infant milk.Postgraduate: Liu FangMajor: Food ScienceSupervisor: Prof. Huo Guicheng...