논문 상세보기
pp.151-158
액상요구르트의 제조시에 분유에 의한 산생성불량의 원인을 규명하고 이의 개선방법을 검토하였다. TCA-soluble peptides이 함량이 낮은 탈지분유는 모두 요구르트 제조시에 산생성이 불량하였고, TCA-soluble peptides의 함량이 높은 탈지분유는 모두 산생성이 양호하였다. TCA-soluble peptides의 함량이 낮은 불량탈지분유에 Na-caseinate의 trypsin 분해물 첨가는젖산균의 산생성을 촉진시켰다. 그러나 Na-caseinate의 papain 분해물 첨가는 촉진효과를 나타내지 못했고, 세균성 중성 protease 분해물의 첨가는 억제 효과를 나타내었다. Na-caseinate의 trypsin 분해물 첨가는 탈지분유의 TCA-soluble peptides 함량이 낮고 starter 젖산균의 단백질 분해능력이 약할 경우에 젖산균의 증식 촉진효과와 산생성 촉진효과가 크게 나타났다. TCA-soluble peptides의 함량이 부족한 탈지분유에 Na-caseinate 미분해물을 첨가하여 발효시킨 액상요구르트는 유단백질의 침전이 발생하였으나, Na-caseinate의 trypsin 분해물을 첨가하여 제조한 것은 정상적인 탈지분유에서와 같이 단백질의 침전이 발생하지 않았다.
This study was carried out to clear up the cause of low-acid producing phenomenon occurred in non-fat dry milk during liquid-yoghurt fermentation by Lactobacillus casei, and to present its improving methods. All samples of non-fat dry milks which were low in TCA-soluble peptides showed low-acid production, but those high in TCA-soluble peptides showed high-acid production. The addition of trypsin-hydrolysate of Na-casein-ate to non-fat dry milk showed some improving effect on acid production but that of papain-hydrolysate did not show any improving effect and that of bacterical neutral protease-hydrolysate showed some inhibitory effect. The improving effects on growth and acid production of lactic acid bacteria were more prominent when the trypsin-hydrolysate of Na-caseinate was added to such fermenting system in which the levels of TCA-soluble peptides and the proteolytic ability of starter bacteria were abnormally low. The liquid-yoghurt made with non-hydrolysed Na-caseinate and defective non-fat dry milk showed precipitate occurrence but that with trypsin-hydrolysate of Na-caseinate and defective non-fat dry milk did not make any precipitate during storage as with normal non-fat dry milk.
