Trehalose와 당류가 냉동요구르트의 저장 중 유산균 생존율과 품질특성에 미치는 영향

Effect of Trehalose and Sugar Alcohol on the Viability of Lactic Acid Bacteria and Quality Characteristics during Frozen Storage of Yoghurt

  • 우성호 (강원대학교 동물생명과학대학 동물식품응용과학과) ;
  • 주진우 (강원대학교 동물생명과학대학 동물식품응용과학과) ;
  • 윤원병 (강원대학교 BT특성화대학 식품생명공학전공) ;
  • 김거유 (강원대학교 동물생명과학대학 동물식품응용과학과)
  • Woo, Sung-Ho (Department of Animal Products and Food Science, Kangwon National University) ;
  • Jhoo, Jin-Woo (Department of Animal Products and Food Science, Kangwon National University) ;
  • Yoon, Won-Byong (Department of Food Science and Biotechnology, Kangwon National University) ;
  • Kim, Gur-Yoo (Department of Animal Products and Food Science, Kangwon National University)
  • 발행 : 2010.02.28

초록

본 연구에서는 냉동요구르트 제조 시 trehalose와 sorbitol 첨가가 유산균의 동결변성방지 및 향기성분의 변화에 미치는 영향을 조사하고자 실시하였다. 요구르트를 L. bulgaricus와 S. thermophilus 단독균주 및 혼합균주로 발효시켰을 때 처리구 모두 trehalose와 sorbitol 첨가에 의한 발효과정 중 유산균의 증식효과는 나타나지 않았다. 요구르트를 6주간 냉동저장하는 동안 trehalose와 sorbitol 첨가에 의한 모든 처리구에서 유산균수의 차이가 없었으며, MRS 액상배지에 trehalose와 sorbitol 을 각각 2%, 5% 첨가하여 6주간 냉동저장하였을 때는 5% trehalose 처리구의 동결변성방지 효과가 가장 우수한 것으로 나타났다. 냉동저장 기간 동안 고형분 함량이 12%인 처리구와 20%인 처리구의 생균수는 큰 차이가 나타나지 않아 고형분 함량 차이에 의한 trehalose와 sorbitol 효과에는 차이가 없는 결과를 나타내었다. 요구르트의 동결과 해동을 반복하였을 경우 trehalose와 sorbitol 모두 2% 첨가구보다 5% 첨가구가 우수한 동결변성방지 효과를 나타내었다. 전반적으로 Trehalose 첨가구가 sorbitol 첨가구보다 2%, 5% 모두 동결변성방지 효과가 좋은 결과를 나타내었다. Trehalose와 sorbitol을 첨가하여 요구르트를 제조하였을때 향미성분의 함량은 대조구와 유사하였으며 일반적인 요구르트의 향미를 나타내었다. 냉동저장 중 요구르트 향미성분은 손실되거나, 함량비율의 변화가 발생하지 않았다. 이상의 결과로부터 요구르트의 풍미에는 영향을 미치지 않으면서 냉동저장에 의한 유산균의 동결변성방지제로서의 trehalose첨가가 냉동요구르트의 유산균 안정화에 효과가 있다고 하겠다.

The objective of the current study was to determine the cryoprotective effects of trehaolse on lactic acid bacteria in the frozen yoghurt during long-term frozen storage conditions. The frozen yoghurts were prepared using starter culture containing Lactobacillus bulgaricus and Streptococcus thermophilus, as well as trehalose and sorbitol as a cryoprotectant. The viable cell numbers of lactic acid bacteria in frozen yoghurt did not significantly decreased during six weeks frozen storage conditions. The MRS broth, which contains either trehalose or sorbitol, cultured with L. bulgaricus and/or S. thermophilus, and then the cultured medium was kept in the frozen condition for six weeks. The results indicated that lactic acid bacteria viability significantly increased with trehalose addition (2 and 5%) in the media compared to those of control and sorbitol supplement groups. The lactic acid bacteria viability in the yoghurts was examined on the effects of repeated freeze and thaw events. The freeze-thaw resistance of lactic acid bacteria significantly increased with trehalose supplement in the yoghurt. The major volatile aroma compounds (acetaldehyde, acetone, ethanol, diacetyl, and acetoin) in yoghurt were separated and indentified by headspace GC-FID analysis. Distinct flavor components and their ratios are known as important quality factors for yoghurt notes. Trehalose addition to the yoghurt was not influenced these factors during lactic acid fermentation. The results in this study demonstrated that trehalose potentially can be applicable as an effective cryoprotectant for lactic acid bacteria in the frozen yoghurt products.

키워드

참고문헌

  1. Badings HT, Neeter R. 1980. Recent advances in the study of aroma compounds of milk and dairy products. Neth. Milk Dairy J. 34: 9-13
  2. Crowe JH, Crowe LM, Carpenter JF, Rudolph AS, Wistrom CA, Spargo BJ, Anchordoguy TJ. 1988. Interactions of sugars with membranes. Biochim. Biophys. Acta. 947: 367-384 https://doi.org/10.1016/0304-4157(88)90015-9
  3. Guinard JX, Little C, Marty C, Palchak TR. 1994. Effect of frozen yoghurt to a student population. J. Dairy Sci. 77: 1232-1238 https://doi.org/10.3168/jds.S0022-0302(94)77062-4
  4. Guinard JX, Little C, Marty C, Palchak TR. 1994. Effect of sugar and acid on the acceptability of frozen yoghurt to a student population. J. Dairy Sci. 77: 1232-1238 https://doi.org/10.3168/jds.S0022-0302(94)77062-4
  5. Kang YJ, Frank JF, Lillard DA. 1988. Gas chromatographic detection of yoghurt flavor compounds and changes during refrigerated storage. Cult. Dairy Prod. J. 4: 6-9
  6. Kim ER, Kim YS, Lee YG, Ju GS, Lee GI, Baick SC, Lee GI, Yu JH. 1996. Effect of sorbitol on the texture and the survival of lactic acid bacteria of frozen yoghurt. Korean Dairy Technol. 14: 71-84
  7. Kim KH, Ko YT. 1993. Volatile aroma compounds of yoghurt from milk and cereals. Korean J. Food Sci. Technol. 25: 136-141
  8. Kirsop BE. 1991. General introduction to maintenance methods. In: Maintenance of microorganism and cultured cells. Kirsop BE, Doyle A (eds). Academic Press, London, UK, pp. 21-30
  9. Knupp JR. 1979. Frozen yoghurt. Cult. Dairy Prod. J. 14: 16-19
  10. Ku KY, Cho JS, Park WS, Nam YJ. 1999. Effects of sorbitol and sugar sources on the fermentation and sensory properties of baechu kimchi. Korean J. Food Sci. Technol. 31:794-801
  11. Kwak HS. 1995. Effect of volatile flavor compound on yoghurt during refrigerated storage. Korean J. Food Sci. Technol. 27: 939-943
  12. Lloyd GT. 1975. The production of concentrated starters by batch culture: Ⅱ. Studies on the optimum storage temperature. Aust. J. Dairy Technol. 107-108
  13. Miller DP, de Pablo JJ, Corti HR. 1997. Thermo-physical properties of trehalose and its concentrated aqueous solutions. Pharm. Res. 14: 578-590 https://doi.org/10.1023/A:1012192725996
  14. Pringle MJ, Chapman D. 1981. Biomembrane structure and effects of temperature. In: Effects of low temperature on biological systems. Morris GJ, Clarke A (eds). Academic Press, New York, USA, pp. 21-25
  15. Rasic JL, Kurmann JA. 1978. Yoghurt: scientific grounds, technology, manufacture and preparation. Technical Dairy Publishing House, Copenhagen, Denmark, p. 90
  16. Roser B. 1991. Trehalose, a new approach to premium dried foods. Trends Food Sci. Tech. 2: 166-169 https://doi.org/10.1016/0924-2244(91)90671-5
  17. Takanobu H. 2002. Novel functions and applications of trehalose. Pure Appl. Chem. 74: 1263-1269 https://doi.org/10.1351/pac200274071263
  18. Thompson LD, Mistry AN. 1994. Compositional changes in frozen yogurt during fermentation, frozen storage, and soft serve freezing. Cult. Dairy Prod. J. 29: 12-17