Preparation of micro hydrogel beads composed of fermented soy milk and okara and the evaluation its releasing properties

Abstract

近年來國人健康意識抬頭 於 2014 年健康食品市場產值上看 850，億元新台幣 其原料來源廣泛 以植物的使用位居首位 黃豆 (soybean)。為我國常食用之豆類原料，含有豐富之營養物質及機能性成分，統計資料顯示黃豆粉及其細粒總量全年之進口量達 1904,829 公噸，由於其具有獨特風味廣受國人喜愛，在豆類製品的加工過程中，豆渣(okara) 為主要副產物，我國每年產生的豆渣數量高達 58 公噸，其水分及蛋白質含量高，亦可作為膳食纖維的良好來源。益生菌及其相關製品亦為近年來保健食品之熱門主題，因此，本實驗探討豆渣之機能性成分分析及理化特性評估，並探討以果膠及阿拉伯膠之混合膠體製備具機能性之發酵豆乳 complex 式膠球造粒品質及益生菌之存活率，最後評估其體外模擬釋放試驗。

本實驗結果如下：豆漿與豆渣混合共同發酵之最佳比例為SM60O1，其發酵 24 hr 後之菌數達 8.76 log CFU/ml，pH 值為 4.15，總多酚和類黃酮分別為 0.59 mg gallic acid eq./ g dw 和 0.24 mgquercetin acid eq./ g dw，總醣及可滴定酸為 1.64 mg/ml 和 0.41%。不同粒徑之豆渣纖維其粒徑分佈分別為 416.48、304.92、185.51、48.48及 20.30 μm，其中以 416.48 μm (20 mesh) 有最佳的保水力、膨潤力和保油力，分別為 9.12、16.46 及 3.51 ml/g。果膠與阿拉伯膠混合比例以 1% P3A2 complex 式膠球為最適製備載體條件 其含水率及膨潤，力分別為 96.85 及 230.13%，硬度測試 4865.6 g，熱焓分析 98.4 J/g。發酵豆乳機能性膠球以 SM1G2 有最佳的鍵結強度，含水率及膨潤力分別為 99.72 及 180.36%，硬度測試 3500.67 g，熱焓分析 33.23 J/g，於 pH 1.2 及 2.0 的模擬胃液中，SM1G2 之菌體耐受性較佳，其存活率分別為 57.29 和 95.37%，在胃腸連續釋放試驗中，菌體之釋放量達7.31 log CFU/ml。

Recently, health conscious of national people raising up results in output value of functional food increasing. The output value is about 85,000 million NT dollars in 2014. The cereals are the largest source of functional foods materials. Soybean is a regular consumption in Taiwan and it is rich in nutrients and functional compounds. The soybean amount of input in Taiwan is 173,469 tons in a whole year. Besides, soybean is a popular food because of unique flavor. Okara is a main by-product during the processing of soybean products. The annual output of okara was over 366,019 tons in Taiwan. It is abundant in moisture, protein and dietary fiber content. Recently, probiotics and related products are popular topic. Therefore, this research study on fermentation liquid, okara and micro hydrogel beads.

The results show that the best ratio of soybean milk and okara, components of fermentation liquid, is 60:1 named SM60O1. After 24 hours fermentation, the microbial counts, pH value, total phenolic compounds content, total flavonoid content, carbohydrate content and titratable acidity are 8.76 log CFU/ml, 4.15, 0.59 mg/g dw, 0.24 mg/g dw, 1.64 mg/ml and 0.41%. Particle size results of okara fiber treated by different extents of micronized processing are 416.48, 304.92, 185.51, 48.48 and 20.30 μm. Moreover, the 20-mesh group, mean particle size is 416.48μm, has the best water-holding capacity, swelling capacity and oil-holding capacity, 9.12, 16.46 and 3.51 ml/g respectively. The complex hydrogel bead is made by 7.5% pectin and 1 % arabic gum and the ratio of them is 3:2. It is the best prepared condition and named P3A2. The moisture content, swelling capacity, hardness and enthalpy analysis of this complex hydrogel bead are 96.85%, 230.13%, 4865.6 g and 98.4 J/g. The functional hydrogel bead named SM1G2, means the ratio of soybean milk and gel is 1:2, has the best strength of bonding structure. The moisture content, swelling capacity, hardness and enthalpy analysis are 99.72%, 180.36%, 3500.67 g and 33.23 J/g. Moreover, the probiotic survival rate of SM1G2 in the stimulate gastric juice, pH value are 1.2 and 2.0, are 57.29 and 95.37%. And the microbial counts of releasing test in the intestinal liquid, after stimulate gastric juice, is 7.31 log CFU/ml. In this study, the best condition is SM1G2 functional hydrogel bead. The best concentration and ratio of mixed gel are 1 % and 3:2 of arabic gum and pectin.