复合酶解结合超高压技术制备香蕉汁的工艺优化

Technology optimization for preparation of banana juice by combining composite enzymatic hydrolysis with high hydrostatic pressure

利用复合酶解结合超高压技术制备香蕉汁,以提高香蕉的出汁率和品质。首先优化得到了出汁率的最佳酶解条件,而后进一步考察了不同超高压处理对香蕉汁色泽、褐变度和菌落总数等指标的影响;通过最佳酶解工艺制汁和450MPa,10min超高压处理香蕉汁后,采用固相微萃取与气相色谱质谱仪(gas chromatography-mass spectrometer)联用检测,考察其香气成分的变化。研究结果表明:适于实际生产的酶解工艺为:酶添加量为0.025%,酶解时间为1.5h,酶解温度为35℃,pH值为4.0,在此工艺条件下香蕉出汁率为81.6%;超高压处理可以抑制香蕉汁的褐变,且对香蕉汁色泽具有很好的保护作用,其中450MPa压力处理效果最好;超高压的杀菌效果随压力的增加而增强,经450MPa处理后,细菌死亡率达到90.25%,菌落总数可降至10cfu/mL以下;超高压处理使香蕉汁中醛类物质相对含量下降,烯类物质相对含量提高,但对整体香气组分的质量分数影响不大。为香蕉的深加工利用提供了新的方法。

Dajiao is an excellent potential raw material for industrial banana procession. Musa ABB group Dongguang dajiao was used as raw material to prepare banana juice. In order to increase yield and improve the quality of banana juice, composite enzymatic hydrolysis （Unikpectinase FM, containing cellulase, pectinase, glucanase, xylanase） and high hydrostatic pressure （HHP） processing with highly effective bactericidal effect were introduced in the preparation of Dajiao juice. The combined technique can keep the original flavor, color and nutritional components. Moreover it showed low energy consumption and non-pollution to the environment. Firstly, the optimal enzymatic hydrolysis conditions were obtained by orthogonal design with the juice rate as the index, every measuring datum was repeated 3 times and an average was applied. Secondly, banana juice prepared by the optimal enzymatic hydrolysis conditions was processed by HHP, respectively in 0.1 （untreated control group）, 150, 300 and 450 MPa for 10 min. The effects of different pressure treatments on the colour, browning degree and colony count of banana juice were studied. According to the results of orthogonal experiment and considering the demand of practical production, the optimum conditions of enzymatic hydrolysis were as follows：the enzyme amount 0.025%, time 1.5h, temperature 35℃, pH value 4, and the juice yield under these optimum conditions was 81.6%. HHP had a very good protective effect on the color of Dajiao juice. The bactericidal effect was improved with the increase of the pressure level. After the treatment of HHP at 450 MPa for 10 min, the count of total bacteria was decreased to 10 cfu/mL by 90.25%. The aroma components in banana juice before and after HHP treatment were analyzed by combining solid phase micro extraction （SPME） with gas chromatography mass spectrometry （GC-MS） method, investigating the changes of the aroma components. The data were subjected to analysis of variance using the SPSS1.7.3. Statistical significance was defined as p〈0.05. After HHP treatment, the aldehydes content was decreased significantly and the alkenes content was increased significantly in banana juice. HHP treatment induced little on the overall aroma perception of banana juice. This study provides a new way for deep-processing of banana.