【作者】 郑淑彦；

【导师】 李志西；

【作者基本信息】 西北农林科技大学 ， 粮食、油脂及植物蛋白工程， 2011， 硕士

【摘要】 果醋以其独特的口感风味、营养价值和保健功能越来越受到大众的喜爱。现代研究表明，果醋具有抗氧化作用，在预防和治疗高血脂及心血管疾病方面具有一定的功效。本研究以新鲜枳椇果梗为原料，测定了枳椇果梗的主要化学成分；研究了酒精发酵中枳椇原料的处理方式；采用液态深层发酵法酿造枳椇醋，探讨了枳椇酒精发酵和醋酸发酵时期各主要成分、抗氧化物质及抗氧化能力的变化趋势；分析比较了枳椇酒醪和枳椇醋浓缩液与馏出物的抗氧化物质及抗氧化能力；对枳椇酒醪和枳椇醋的有机溶剂萃取物中的抗氧化物质和抗氧化能力进行了分析。得到以下主要研究结果：（1）新鲜枳椇果梗主要化学成分的测定结果表明：新鲜果梗水分含量为51.98%，总酸为0.7g/100mL（以柠檬酸计），总糖为36.51g /100g鲜重（以葡萄糖计），还原糖为22.37g/100g鲜重（以葡萄糖计），总Vc为47.43 mg /100g鲜重（以抗坏血酸计）。总酚含量为267.27mg/100g鲜重（以原儿茶酸计），总黄酮含量为185.20mg /100g鲜重（以芦丁计）。（2）以酒度、出酒率、总酸度和总Vc含量为指标比较不同处理方式对枳椇酒醪的影响，结果表明：枳椇果梗的三种不同处理方式中，破碎发酵较直接发酵和破碎加酶发酵的各指标值均高。（3）对酒精发酵过程中还原糖、可溶性固形物、酒度、总酸、pH值、总酚、总黄酮、DPPH自由基清除能力和还原能力的变化的研究表明：可溶性固形物和还原糖含量在发酵初期稍有增加，随后急剧下降，后期基本保持不变；酒度在发酵初期缓慢增加，然后迅速增加，后期基本保持不变；酸度呈缓慢上升的趋势，幅度不大；pH值呈先下降后平稳的变化趋势。总酚含量总体呈上升的趋势，但在发酵过程有一定波动；总黄酮含量呈上升趋势；DPPH自由基清除能力随时间的延长而增强；还原能力在发酵期间有一定的波动，但幅度不大，无明显变化。（4）对醋酸发酵过程中发酵液酒度、酸度、pH值、总酚、总黄酮、DPPH自由基清除能力、还原能力的测定结果表明：醋酸发酵的启动阶段和正常发酵阶段各主要成分及抗氧化能力的变化趋势一致，初期酒度先缓慢下降，随后迅速下降，然后趋于稳定；初期酸度缓慢上升，随后迅速上升，然后趋于稳定；pH值呈逐渐下降的趋势。总酚含量总体呈下降趋势，但有波动；总黄酮含量呈先下降后上升的趋势；DPPH自由基清除能力和还原能力均呈下降的趋势。（5）枳椇酒醪及其浓缩液和枳椇醋及其浓缩液均具有较强的抗氧化能力，其馏出物几乎不具有抗氧化能力。（6）采用不同极性的有机溶剂萃取枳椇酒醪和枳椇醋，对其不同极性组分的抗氧化能力进行测定，结果表明：枳椇酒醪萃取物得率的大小依次为水残留物>正丁醇萃取物>乙酸乙酯萃取物>氯仿萃取物；枳椇醋为正丁醇萃取物>水残留物>乙酸乙酯萃取物>氯仿萃取物；氯仿萃取物的DPPH自由基清除能力最高，乙酸乙酯萃取物稍弱于氯仿萃取物，而水残留物的能力最弱，萃取物的总酚含量、总黄酮含量和DPPH自由基清除能力的趋势一致，表明酚类物质和黄酮类物质与抗氧化能力密切相关。更多还原

【Abstract】 The fruit vinegar is more and more popular for its unique flavor, taste, nutritional valueand healthy functions. The modern research shows that the fruit vinegar possessesantioxidational effects which can prevent and treat high blood cholesterol and cardiovasculardisease.The purpose of this study was to investigate the main components of stems; thetreatment of stems in the alcoholic fermentation; the changes of the main component,antioxidants and antioxidant capacity were researched in alcoholic fermentation andacetic acid fermentation. The antioxidants and antioxidant capacity of Hovenia dulcisThunb wine, vinegar and their concentrate and distillates were analysed and compared.The antioxidants and antioxidant capacity of Hovenia dulcis Thunb wine, vinegar indifferent solvent extracts were compared and analysed in correlation with them. Themain results are as follows:（1）The main chemical compositions of fresh Hovenia dulcis Thunb stems were testedfor 51.98% moisture content, 0.7g/100mL total acid (citric acid). The total sugar was 36.51g/100g fresh weight (glucose), reducing sugar was 22.37 g /100g fresh weight (glucose), totalascorbic acidcontent was 47.43 mg / 100g fresh weight (ascorbic acid), total phenol contentwas 267.27mg / 100g fresh weight (protocatechuic acid), total flavonoid content was 185.20mg /100g fresh weight (rutin).（2）The Hovenia dulcis Thunb stems were treated in three different ways by comparingthe alcohol content, juice yield, total acidity and total Vc of Hovenia dulcis Thunb fruit wine.The indexes of crushing fermentation were higher compared with direct fermentation andenzyme fermentation.（3）The changes of indexes were tested in alcoholic fermentation. Soluble solids andreducing sugar content with time showed a slight increase at first, then sharp decline andfinally remained the same. The alcohol was slowly increased at first, then rapidly increasedand finally remained unchanged. The acidity had upward trend. pH values were stable afterthe first decline in the trend. Fluctuation in the total phenol content, the overall was upward trend. Upward trend was in total flavonoids. DPPH radical scavenging ability was enhancedwith time. Reducing power had fluctuation but no significant change.（4）The changes of indexes were tested in acetic acid fermentation. The experimentfound that the change of indexes in start-up phase was similar to the ones in rapid phase.Alcohol decreased slowly at first, then quickly, at last stayed stably; after acidity rase slowlyat first, it increased rapidly and at last stayed stably; pH value was declining slowly.Fluctuation in the total phenol content, the overall was downward trend; total flavonoidcontent was firstly decreased and then increased; DPPH radical scavenging ability decreasedwith time; reducing power was downward trend.（5）The antioxidants and antioxidant capacity of Hovenia dulcis Thunb wine, vinegarand their concentrate and distillates were analysed and compared by DPPH radical scavengingability, total phenol and total flavonoids. Hovenia dulcis Thunb wine, vinegar and theirconcentrate had strong antioxidant capacity, and theirs distillates almost had no antioxidantcapacity.（6）The antioxidants and antioxidant capacity of Hovenia dulcis Thunb wine, vinegar indifferent solvent extracts were compared and analysed. The yield of each wine extract was:water residue> butanol extract> ethyl acetate extract> chloroform extract; the yield of eachvinegar extract was: butanol extract> water residue> ethyl acetate extract> chloroform extract.The highest DPPH radical scavenging ability was in the chloroform extract. The ability in theethyl acetate extract was weaker than one in chloroform extract, and one was the weakest inthe water residues. There were the same trend between total phenolic content, total flavonoidcontent and DPPH radical scavenging capacity, which revealed phenols and flavonoids wererelated with antioxidant capacity.更多还原