香蕉深加工关键技术研究

香蕉深加工关键技术研究摘要香蕉是世界第四大水果，产量高，营养丰富，保健功能特别突出，除了能促进肠蠕动，防止便秘外，还有抗氧化、降血脂、降血压、降血糖、防止动脉硬化等功能，2005年被誉为“新水果之王”。

但香蕉加工特性及加工技术研究不多，水平很低。

严重影响了香蕉的深加工和综合利用。

本文以香蕉的三个主要品种巴西蕉、粉蕉、大蕉为试验材料，全面研究了香蕉的护色、加工特性，重点对香蕉淀粉的理化指标及其特性进行了较为深入的研究。

研究发现酶促褐变是香蕉褐变的主要原因；对香蕉打浆护色的不同条件（温度和O2）进行了系统研究，研究护色剂在香蕉加工过程中的护色效果，对护色条件进行了优化；探讨了液氮对香蕉打浆过程的影响规律，得到了适宜的打浆护色方法；初步研究了香蕉淀粉提取工艺，并对工艺参数进行了优化；采用微波灭酶、超高压杀菌生产香蕉汁的工艺研究和探讨了香蕉挤压膨化的制备工艺。

主要结果如下：1. 香蕉淀粉的特性主要研究了香蕉淀粉颗粒的大小、偏光十字、x-衍射图谱和晶结构，测定了香蕉淀粉糊的透光率、凝沉性、冻融性等性质。

结果表明：香蕉淀粉糊透光率低、冻融性差、凝沉好。

香蕉淀粉糊的粘度随着pH值的升高而增加，食盐和蔗糖有利于提高其粘度。

香蕉（大蕉、粉蕉、巴西蕉）淀粉中直链淀粉平均含量分别为20.14%、26.25%、14.21%(干基)；香蕉（巴西蕉、淀粉、大蕉）淀粉的初始糊化温度分别为68℃、66.9℃、67.9℃，较马铃薯淀粉糊化温度低；香蕉淀粉糊的粘度热稳定性、凝胶性和凝沉性均高于马铃薯淀粉；但香蕉淀粉糊的冷粘度稳定性、透明度和冻融稳定性均低于马铃薯淀粉糊；香蕉淀粉糊冻融稳定性与玉米淀粉糊相当。

2. 香蕉浆的护色研究褐变是香蕉加工的首要难题，酶促褐变是导致香蕉皮褐变的主要因素。

研究发现香蕉PPO的最适温度为20～35℃，30℃时酶活力最大，低于20℃酶活力较低，高于40℃开始被逐渐钝化。

POD的最适温度为35～45℃之间，在40℃酶活力最大，同PPO趋势一样，温度过高或过低，酶活都会受到抑制。

研究发现POD 比PPO更耐热，所以在香蕉加工过程中应以POD失活作为香蕉钝酶充分的标志。

采用二次旋转回归的方法，研究了香蕉浆灭酶过程中通过添加护色剂亚硫酸氢钠进行护色的工艺，得到最佳护色的条件为：微波灭酶时间80s、加1.5倍的水、亚硫酸氢钠添加量为30mg/L。

又以液氮为护色剂进行护色研究，在打浆过程中添加香蕉浆重量约1%~2%的液氮，使香蕉浆的温度降低10±1℃，同时减少香蕉浆中50.4%的氧气含量，进一步有效抑制了香蕉加工过程中的褐变，还可提高香蕉的出汁率。

3. 香蕉系列产品深加工及其综合利用（1）香蕉淀粉的提取采用正交设计对提取工艺进行优化，得到最佳提取条件为料液比1∶2、温度50℃、酶解时间40min，此时淀粉得率为10.23%。

（2）香蕉汁的生产通过单参数优化、多参数优化，获得了护色、打浆、酶解、榨汁、微滤、超高压灭菌、无菌包装的香蕉汁工艺；打浆时香蕉与水的比例为1:1，加入液氮进行护色，使浆体温度降10±1℃；微波灭酶时间80s，并迅速冷却至50℃左右；然后在45℃条件下降解果胶，果胶酶添加量为70mg/L，酶解时间70min；离心分离，膜过滤，灭菌，无菌灌装后冷却至室温，即得香蕉汁成品。

香蕉汁的理化指标为：糖度11ºBx，pH值为4.26，透光率96.1%, 且色泽、风味较好。

（3）对香蕉皮渣的综合利用进行了初步研究。

关键词:香蕉；加工；护色；淀粉研究RESEARCH ON BANANA PROCESSING TECHNOLOGYABSTRACTBanana is the forth staple fruit of the world. It is high in yielding, with affluent nutrition, especially prominence in the health care function. Except for promoting the intestines’ wriggl ing, it also have function of anti-oxidation, depressing blood fats, descent the blood pressure, lower the blood sugar, preventing arteriosclerosis and so on. In 2005, it is giving the title of “the new king of fruit”. But the research es of banana processing characteristics and its processing technique are not too much; and the research level is not so high either. Therefore, it seriously affected banana's deep processing and the comprehensive utilization.Using three main breeds of banana - Baxijiao, Fenjiao and Dajiao as this research’s experimental material, it comprehensively studied the banana’s color protection, processing characteristic, and mainly focus on analyzing banana starch’s physiochemical properties and characteristic. The research discovered that the enzymatic browning is the main reason of banana turning brown; systematically studied the effects of banana grinding condition (temperature and O2), and optimized the color protect condition by studying the effect when adding certain agent; Probed into the influencing rules adding liquid nitrogen when grinding process, and then obtained the optimized suitable method to color protection; Primary studied the banana starch isolated and distilled craft, and optimized the craft parameter; Studied banana juice processing craft of extinguishing the enzyme by microwave, ultra-high pressure sterilization and discussed the spurting craft of banana pomace to be produced Puffs food. The research contents and results in details are following:1. The characteristics of banana starchThe properties of banana starch were studied, including size, polarization cross, X-ray diffraction pattern and Crystallization structure etc. The pastes properties of banana starch such as translucency, retrogradation, and freeze-thaw were studied. Theresults showed that banana starch pastes have properties of lower clarity, poor freeze-thaw stability and good retrogradation. The viscidity of banana starch pastes increased with rising of pH value, the salt and cane sugar help to raise their viscidity. Amylose contents of banana starch from Dajiao, Fenjiao and Baxijiao were 20.14%, 26.25%, 14.21%；the pasting temperature respectively were 68℃, 66.9℃, 67.9℃；its viscidity thermostability remarkably is higher than the potato starch’s, the retrogradation and freeze-thaw to be higher than the potato starch; But the banana starch sticks the cold viscosity stability, the transparency and the freeze-thaw stability are lower than the potato starch to stick; The banana starch sticks the freez-thaw stability with the corn starch sticks quite.2. The research of keeping banana slurry colorBrowing is the key problem in banana processing. The major cause is enzymatic browning. The characteristics of polyphenol oxidase (PPO) and peroxides (POD) from banana were studied. The results showed that the optimum temperature of PPO was 30℃, POD was 40℃. Excessively high or low temperature causes the suppression of enzyme activity. POD is more heat-resisting than PPO. So the symbol of the enzyme was extinguished thoroughly by the POD deactivation in the banana processing process.The method of inactivating enzymes by microwave was studied through experiments of quadratic regressive rotation in this paper. Then, the best color keeping process of banana plasm was gained by analyzing such factors as time, proportion of adding water, and the amount of color protecting additive. It discussed the influencing rules when adding liquid nitrogen in the grinding process, the temperature of banana slurry was lowered to10 1℃, and the oxygen content of banana slurry was reduced to its 50.4 percent, and then obtained the optimized condition of blending; the yield of banana juice was improved too.3. Series banana products processing and its comprehensive utilization(1) B anana starch’s extractionThe optimum conditions for extraction were: 200g Fenjiao to be beaten into slurry (The ratio of banana to water is 2:1(g/g)), enzyme adding quantity: respectively 0.07, 0.08, 0.09 and 0.10g/kg, 45℃, reacting time: 70min, repeated 4 times. Result turns to be correspondingly: 11.624g, 8.111g, 10.487g, and 7.740g. Integrative consideration according to cost and etc. factors, it was determined that 0.07g/kg as the final adding quantity. Under the condition of enzyme’s adding quantity of 0.07g/kg,45℃, reaction time: 30min, 50min, 70min, 90min, then ensure 50-60min’s gelatine removing effect is better. Optimize the processing technique by adopting orthogonal design, obtain the optimal extracting condition is mater – liquid ratio: 1:2, temperature: 50℃, enzyme’s reaction time: 40min, and herein, the extracting yield reached 10.23%.(2) Banana juice productionThe ratio of banana to water is 1:1(g/g)，adding liquid nitrogen with rations to protect banana slurry color from becoming brown, the temperature of slurry dropped to 10 1℃; inactive enzyme 80s by microwave，then to be cooled to 50℃; 70 mg/L pectinase at 45℃, the time of decompose was 70min, centrifugal separate, filtrated with super filtrate film，400MPa40℃5min UHT sterilized，asepsis perfusion and then cooled down to room temperature. The physical and chemical analysis of banana juice was: 11ºBx, pH4.26, ray permeated rate: 96.1%, its color and flavor are good.(3)Banana marc made to be puff foodThe banana marc, which is the remaining of the banana juice making, is pressed and extruded though the double-shaft inflation machine. The products were extracted from banana skin, such as pectin, dietary fiber etc. would be used as resource to the furthest extend, meanwhile, reducing the pollution.KEY WORDS: banana, process, color protection, starch research。