Abstract: In this experiment, citrus fiber, beet fiber and agar were used to develop a low-sugar, high-fiber room-temperature fermented yogurt, and the texture and sensory quality of yogurt samples made with their combinations in different proportions were evaluated. Lactase and Sweety T-1, a mixed commercial starter culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus were used to completely decompose lactose in milk to produce glucose with higher sweetness, thereby improving the sweetness of low-sugar yogurt. The results showed that adding 3% citrus fiber, 0.2% agar and 1% beet fiber imparted good stability and high sensory score to low-sugar, high-fiber room-temperature fermented yogurt. Raw milk was inoculated 200 U/L Sweety T-1 with the addition of 1 600 BLU/L lactase and without the addition of any sugar or sweetener and was fermented at 42 ℃. After 12 h, lactose was completely decomposed, producing 2.5% glucose.

Key words: room-temperature fermented milk, low-sugar, high-fiber, formulation optimization, stability, lactose, glucose

摘要： 以柑橘纤维、甜菜纤维和琼脂构建低糖高纤维常温发酵乳体系，探究不同添加量组合下产品质构及感官品质。同时利用乳糖酶和Sweety T-1发酵剂分解产品中全部乳糖，并转化为甜度更高的葡萄糖，从而提高低糖发酵乳的甜度。结果表明：添加3%柑橘纤维、0.2%琼脂和1%甜菜纤维可构建质构优良、稳定性好且感官评分高的低糖高纤维常温发酵乳体系；在不添加其他增甜物质的基础上，接种200 U/L Sweety T-1发酵剂，42 ℃发酵12 h，同时加入1 600 BLU/L乳糖酶，利用乳糖酶和Sweety T-1发酵剂的协同作用分解全部乳糖，产生2.5%葡萄糖来提高产品甜感，真正实现长保质期发酵乳的低糖和高纤维。

关键词: 常温发酵乳, 低糖, 高纤维, 配方优化, 稳定性, 乳糖, 葡萄糖