Cryoprotectant is a substance used to protect biological tissue from freezing injury. However, there was few research paper on application of cryoprotectant in food stuff although its benefits was approved from the biological cell tissues. The objective of this study was to investigate the effect of the sugar addition as a cryoprotectant on the properties of frozen soybean sprouts. Before freezing process, the samples were blanched at 100°C for 1 min to observe the influence of blanching treatment. The blanched or non-blanched soybean sprouts was immersed in sugar solution as cryoprotectant, and continuously, the samples were frozen at -18°C for 24 h. Their physicochemical properties such as drip loss, hardness, color and cellular tissue were analyzed after thawing in running water. In our study, the drip loss of blanched sample without sugar was 43%, and comparatively, blanched one with sugar was 20% which was the lowest value among all samples. There was no significant difference of hardness between sample with sugar and without sugar. From our results, it was supposed that sugar can protect the soybean sprouts during freezing process regardless blanching process.

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 sorbitol을 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 제조하였을 때 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.

This study was conducted to investigate the effects of type of the sugar supplemented to the extender on the vigor, viability and intact acrosomal rates of frozen-thawed dog spermatozoa. The ejaculated semen was diluted with TRIS-citric acid extender containing 200mM TRIS, 73mM citric acid, 6% (v/v) glycerol, 20% (v/v) egg yolk, 1% (v/v) antibiotics (streptomycin/penicillin), 44 mM sugar, which was either glucose, fructose or glucose-fructose combination, and distilled water to make the final volume of 100ml. Extended semen samples were cooled at for an hour, packaged in 0.25ml straws, equilibrated for 10 minutes in liquid nitrogen vapor, and frozen in liquid nitrogen. Samples were thawed by placing straws into water for 120 seconds. After thawing, vigor, viability and intact acrosomal rates of frozen-thawed semen were compared according to type of sugar. No significant differences were observed between glucose and fructose groups. In addition, combination of the 2 sugars also did not show any significant differences in the vigor, viability and intact acrosomal rates. In conclusion, glucose and fructose were equally efficient as sugar supplements for freezing extender.