Objective:

1. It is hoped to obtain the yogurt process formula of mogroside compound, so as to provide a basis for the development of mogroside yogurt with good flavor and enrich the consumer market of fermented dairy products.

2. The organic combination of mogroside and yoghurt can produce low sugar and sucrose free yoghurt, which can meet the needs of both normal people and obese people and diabetic patients.

Conclusions:

The whole milk powder was used as raw material to prepare the Momoside sweet side yogurt with Momoside sweet side compound of Hunan Nanmo Biotechnology Co., Ltd. The effects of Momoside sweet side compound on yogurt quality, fermentation characteristics, flavor substances and antioxidant capacity were studied, and the following conclusions were drawn:

(1) The taste and flavor of 6 kinds of monkfruit sweet side mixed yogurt were compared by taking into account physical and chemical indexes and sensory scores. Finally, RRT02, which was three times as sweet as sucrose, was selected as the best one.

(2) On the basis of the above experiments, it was found that the water retention and texture of the yoghurt could be changed by adding sucrose to the yoghurt. The water retention of yogurt decreases with the decrease of sucrose. In terms of texture, its consistency changed significantly with the decrease of sucrose addition, showing a trend of first increasing and then decreasing. The consistency was the highest when 40% sucrose (T2) was replaced by monkfruit glucoside, and its diacetyl and acidity changed irregularly with the addition of sucrose.

(3) By changing the supplemental level of monahangoside complex, it was found that the addition of monahangoside complex did not significantly change the texture, water retention, titrated acidity and diacetyl content of yogurt, but had a greater impact on sensory scores. The reason was that too little supplemental level would lead to insufficient sweetness and prominent acidity of yogurt, while excessive supplemental level would lead to greater after-sweetness of yogurt. Both make yogurt taste bad. Combined with sensory score and physicochemical index, T9 (9g/300mL) was determined to be the best in the taste and flavor of sugar-free yogurt.

(4) The effect of monkfruit glycosides on the fermentation characteristics of yogurt during fermentation was studied. The experimental results showed that:

The addition of sucrose can significantly improve the water retention of yoghurt, and the water retention of sucrose yoghurt remains the highest during fermentation. The water retention of yoghurt added without sucrose and monkfruit sweet side is lower than that of monkfruit sweet side mixed yoghurt during fermentation, indicating that adding monkfruit sweet side mixed yoghurt can improve the water retention of yoghurt. During the fermentation period, the titration acidity of the three yogurts showed an increasing trend with the increase of time, and the titration acidity of sucrose yogurts was lower than that of monkfruit sweet side mixed yogurts, with significant difference (P<0.05). During fermentation, the diacetyl content of sucrose yogurt was always lower than that of monkfruit sweet side yogurt and yogurt without sucrose and monkfruit sweet side. During the fermentation period, the diacetyl content of the three yogurts increased first and then tended to be stable with the increase of time. During the whole fermentation period, the diacetyl content of sucrose yogurts was always lower than that of monkfruit sweet side mixed yogurts, with significant difference (P<0.05). There was no significant difference in the content of diacetyl between monkfruit sweet side yogurt and yogurt added with sucrose and monkfruit sweet side compound (P>0.05). During the fermentation period, the viable bacteria count of the three yogurts showed an increasing trend with the increase of fermentation time. The viable bacteria count of sucrose yogurts was slightly higher than that of monkfruit glucoside mixed yogurts and added yogurts without sucrose and monkfruit glucoside. There was no significant difference between the viable bacteria count of monkfruit glucoside mixed yogurts and yogurts without sucrose and monkfruit glucoside added yogurts. These results indicated that the addition of momoside did not affect the normal growth and metabolism of lactic acid bacteria.

(5)The main flavor substances of monkfruit sweet side mixed yogurt and sucrose yogurt were analyzed and compared by GC-MS solid phase microextraction technology. 49 volatile substances were detected in monkfruit sweet side mixed yogurt and 43 volatile substances were detected in sucrose yogurt. The acids of the two yogurts were the main difference between them. The total relative content of monkfruit glycosides was 57.23%, while that of sucrose yogurts was 48.61%. The contents of alcohol, aldehydes, acids, ketones and esters in the mixed yogurt and sucrose yogurt are dispersed and reasonable, and the flavor is soft.

(6) There was no difference in antioxidant capacity among the yoghurt added with monkfruit sweet side compound, sucrose yoghurt, sucrose free yoghurt and monkfruit sweet side compound, indicating that the added amount of monkfruit sweet side compound had no significant effect on antioxidant capacity of yoghurt.