CAJ | 학술논문

凝乳是干酪加工的关键环节,对奶油干酪的品质具有重要影响.通过对奶油干酪理化成分、产率、涂抹性的测定,比较了酶凝、酸凝、酸-酶互作凝乳3种方式对奶油干酪涂抹性的影响.结果表明,随着酸化程度的加深,奶油干酪的脂肪含量和蛋白质含量逐渐减少,含水率显著增加,校正产率、脂肪回收率和酪蛋白回收率降低.有酶高酸组(RHA)涂抹性最佳,其剪切功、屈服应力都分别为最小(19.23 N·s、195.67 Pa),与传统酸凝型奶油干酪(NR)相比,RHA 的剪切功和屈服应力分别降低了17.04%和27.88%,干酪涂抹性得到明显改善.这为涂抹型奶油干酪的研发提供了技术基础.
응유시간락가공적관건배절,대내유간락적품질구유중요영향.통과대내유간락이화성분、산솔、도말성적측정,비교료매응、산응、산-매호작응유3충방식대내유간락도말성적영향.결과표명,수착산화정도적가심,내유간락적지방함량화단백질함량축점감소,함수솔현저증가,교정산솔、지방회수솔화락단백회수솔강저.유매고산조(RHA)도말성최가,기전절공、굴복응력도분별위최소(19.23 N·s、195.67 Pa),여전통산응형내유간락(NR)상비,RHA 적전절공화굴복응력분별강저료17.04%화27.88%,간락도말성득도명현개선.저위도말형내유간락적연발제공료기술기출.
As a kind of fresh cheese spread, spreadability is one of the most important textural properties of cream cheese. Renneting and acidification, as two important coagulation methods, have significant effects on spread ability. There have been great advances in understanding of the effects of acid or rennet induced coagulation on the spreadability of cream cheese, whereas less is understood about how combination of acid and rennet affects its spreadability. So the objective of the present study was to determine the effects of combined acid and rennet on the spread ability of cream cheese. @@@@Combined with texture profile analysis (TPA) and rheological technique, we investigated the effects of coagulation methods on chemical compositions, cheese yield and the spreadability of cream cheese. The coagulation methods in this research included strictly acidification with no rennet (NR), strictly renneting with no acid (NA) and combined acid and rennet with different acidification degrees, rennet with lower acid (RLA), rennet with medium acid (RMA) and rennet with higher acid (RHA). @@@@Cream cheeses with pH values near the isoelectric point exhibited higher moisture, lower fat and protein than those with higher pH values. With combination of acid and rennet, as the cutting pH rising from 4.6 to 6.1, the content of fat and protein in cheese were increased, while the water content was decreased to 47.75%. These results confirmed the remarkable effect of coagulation methods on the composition of cream cheese. On the other hand, coagulation methods also affected the cheese yield and component recoveries. In the rennet or combined acid and rennet induced cheese, there was a significant increase in the yield and component recoveries. In contrast acid-induced cream cheese had lower yield and component recoveries. This could arise from the different changes in the interactions between the casein micelles as a result of rennet and acid action in two ways. Eventually, coagulation methods changed the spreadability. RHA with the lowest shear work (19.23N?s) and yield stress (195.67 Pa) has especially remarkable in spreadability. It was found that rennet-induced cream cheese had higher hardness and was the most difficult to spread. Acid-induced cream cheese had medium spreadability. With the decrease of pH, cream cheese with a combination of acid and rennet coagulation had moderate hardness, smoother texture and was easier to spread. @@@@These results may be attributed to the complex interparticle forces in combination of acid and rennet gels. In rennet gels, casein micelles bond together through hydrophobic and Ca2+-bridging interactions while the aggregating particles coagulate through attractive interactions in the acid gels. So the forces in combination of acid and rennet gels would be different from these strictly acid or rennet gels. For the RHA gels in our research, it formed special structure with the interactions which may contain hydrophobic, Ca2+-bridging and attractive interactions. Rennet with higher acid (RHA) was the best way to produce cream cheese for better spreadability. Apparently, with the coagulation method of combined rennet and acid, the spreadability of cream cheese could be significantly improved.