Optimization of the process of butterfly pea and chia seed yogurt jelly and storage quality analysis

【Objective】 To explore the technological formula and storage quality of butterfly pea and chia seed yogurt jelly, and provide technical support for the development of new jelly products.【Method】 With milk, chia seeds and butterfly pea as the main raw materials, with sensory evaluation as the index, the yogurt jelly of butterfly pea and chia seeds was fermented by single factor experiment and response surface optimization, and its quality during storage was analyzed. 【Result】 The regression model of sensory score(Y) of butterfly pea and chia seeds yoghurt jelly was established by four factors including thickener(pectin:gelatin=1:2) amount(A), fermentation temperature(B), fermentation time(C) and starter amount(D):Y=93.00 + 2.81A + 1.54B + 1.81C + 4.02D + 0.0500AB-0.1250AC + 0.5000AD-0.0750BC + 3.25BD-2.08CD-7.42A²-6.55B²-2.18C²-6.18D². The order of the factors affecting the sensory score of jelly was starter amount> thickener amount>fermentation time>fermentation temperature. Among them, four single factors and the interaction between fermentation temperature and the amount of starter had extremely significant effects on the sensory score of jelly (P<0.01), while fermentation time and starter amount had significant effects on the sensory score of jelly(P<0.05). The optimum fermentation technology and formula of butterfly pea and chia seeds yogurt jelly were as follows:based on the weight of the finished jelly, butterfly pea 1%, chia seeds 1%, purified water 24%, citric acid 0.2%, pure milk 56.9%, thickener(pectin:gelatin=1:2) 3.2%, white sugar 13% and starter 0.7%. When the fermentation temperature was 42℃ and the fermentation time was 7 h, the content of protein in this jelly product was 3.38 g/100 g, the soluble solid content 16.1%, and the number of viable lactic acid bacteria 3.2×10⁸ CFU/mL. After storage at 2-4℃, the shelf life of the product could reach 27 d, gel effect was good, with delicate taste, light blue and yogurt fermentation flavor.【Conclusion】 The yogurt jelly with butterfly pea and chia seeds is optimized by response surface methodology. It is rich in probiotics, protein and dietary fiber. The texture is uniform and elastic,with yogurt fermentation flavor,balanced sweet and sour taste. This study can provide new ideas and directions for the exploitation and utilization of natural resources such as butterfly flower and chia seed, and enrich the variety of jelly products.