【作者】 崔涛；

【导师】 钟海雁；

【作者基本信息】 中南林业科技大学 ， 农产品加工及贮藏工程， 2008， 硕士

【摘要】 砂梨(Pyrus pyrifolia),原产中国长江流域及其以南地区,在20世纪80年代,日本和韩国相继在本土砂梨系统基础上培育出了一些优良的砂梨新品种,近些年来,也一直被我国引种植育。作为一种营养丰富的水果,砂梨具有广阔的发展前景,对其果实及果醋产品的研究对砂梨产业的发展能起到显著的推动作用。本文选取水晶、丰水、雪梨、爱宕四种砂梨为原料,进行了物理性状和基本营养成分的测定,其结果表明：果形指数范围：0.825-0.942,单果重量范围：189.5-324.9g,总酸的范围：0.71%-1.23%,总糖的范围：7.06%-8.53%,还原糖的范围：6.43%7.26%,单宁的范围：0.71%-3.95%,果胶的范围：0.46%-2.00%,维生素C含量范围：1.7-6.8 mg/100g,常量矿物质元素含量较高的是：K(丰水)245.6 mg/100g,Ca(丰水)3.78 mg/100g,Mg(爱宕)24.73 mg/100g,微量元素含量较高的是Fe(爱宕)2.47mg/100g,Zn(水晶)21.34 mg/100g,Mn(水晶)1.06 mg/100g。以水晶梨种作为材料,进行了梨醋酿造实验。实验中采用全固态发酵法进行发酵,并且通过响应曲面法对梨醋酿造配方进行优化,结果显示：醋酸菌接入量为9.6%,初始糖度11.5%,酒精发酵时间120 h,初始酒精度为7.2%,醋酸发酵时间是144 h,pH控制在3.2,可以作为砂梨果醋酿制的最佳工艺条件使用。通过响应曲面法对SPME对砂梨香气成分的萃取条件进行了优化,得出最优萃取条件为：选用PDMS/DVB(65μm)涂层纤维头,萃取温度46℃,萃取时间45 min,盐添加量11%,样品量3.4 g。以此萃取条件,运用HS-SPME结合GC/MS联用技术,对水晶梨及果醋的香气组分进行分析,鉴定出砂梨果实中的32种香气组分和果醋中的15种香气组分。并且采用内标法,对乙酸乙酯、丙酸乙酯、丁酸丁酯、丁醛、5-异丙基-2-甲苯酚、环己烯、丁醇、4-甲基-1-异丙基-3-环己烯-1-醇、丙烯基二氧甲苯酯、2-甲基-丁酸乙酯、已烯酸乙酯、苯丙醇等香气组分进行了定量分析。在对酿制果醋调配后,对果醋的酸度、维生素C含量及部分矿物质元素含量的进行了测定,其结果为：酸度为4.8%,维生素C的含量为3.2(mg/100mL),Ca含量为5.28(mg/100mL), Mg含量为25.58(mg/100mL), Cu含量为0.13(mg/100mL), Fe含量为7.59(mg/100mL), Zn含量为18.07(mg/100mL), As小于等于0.4(μg/100mL), Pb小于等于0.7(μg/100mL),细菌总数小于1400个/mL,大肠菌群数小于3个/100mL,致病菌未检出。各项指标均达标。对果醋的感官评价则用模糊数学法,在模糊数学综合评价方法中,利用加权法对评分进行处理,最终得出结论为一般接受。更多还原

【Abstract】 Sand pear [Pyrus pyrifolia] was originally cultivated in China Yangtze valley and south of the area. In the 1980s, some new cultivars were bred one after another in Japan and South Korea based on the native native sand pear cultivars and have been introduced into our country in recent years. As a type of the nutritional fruits, the sand pear industry has the broad prospects for development. And research of fruit quality and products processing can play the remarkable promoting role to the pear industry development.Cultivars, i.e. Suisho, Hosui, Xuli, and Atago, were selected for determining of the physical characteristics and the basic nutrient content. The result showed that:fruit shape index,0.825-0.942; simple fruit weight,324.9-189.5 g; total acid,0.71%-1.23%; total sugar,7.06%-8.53%; reductant sugar,6.43%-7.26%; tannin,0.71%-3.95%; pectin,0.46 %-2.00%; Vitamin C content,1.7-6.8 mg/100g. The highest level of the main macro-elements among four cultivars was 245.6 mg/100g of K (Hosui),3.78 mg/100g of Ca (Hosui) and 24.73 mg/100g of Mg (Atago), respectively. While,2.47 mg/100g of Fe (Atago),21.34 mg/100g of Zn (Suisho),1.06 mg/100g of Mn (Suisho) was the highest level for relative trace element in above cultivars.The pear vinegar of Suisho was brewed using the solid fermentation. The fermentation condition parameters were optimized by Response Surface Methodology (RSM). The optimum conditions for brewing were:9.6% of inoculation quantity of acetic acid bacteria,11.5% of the initial sugar,120 h of ethyl alcohol fermentation,7.2% of the initial concentration of ethanol,144 h of the acetic fermentation and pH,3.2.Solid Phase Micro-extraction (SPME) for volatile sampling was optimized using RSM. Extraction conditions that gave good total recovery and diversity of compounds from pear slurry headspace were found to be:PDMS/DVB fiber,3.4 g oil sample in 15 mL vessel; exposure for 45 min at 46℃; 11% of salt. The aroma of Suisho and the vinegar were studied by HS-SPME coupled with GC/MS.32 volatile compounds in Suisho fruit and 15 volatile compounds in vinegar, such as ethyl acetate, propanoic acid ethyl ester, butanoic acid butyl ester, butanal, phenol 2-methyl-5-(1-methylthyl), cyclohexene, butanol, 3-cyclohecen-l-ol,4-methyl-1-(1-methylethyl), benzolioxole 5-(2-propenyl), propanoic acid 2-methyl-ethyl ester, hexenoic acid ethyl ester, benzenepropanol and so on were identified and quantitatively analysed using internal standard.4.8% of titrated acidity,3.2 mg/100mL of Vitamin C,5.28 mg/100mL of Ca,25.58 mg/100mL of Mg,0.13mg/100mL of Cu,7.59 mg/100mL of Fe,18.07 mg/100mL of Zn were found in pear vinegar. The hygienic indice of pear vinegar meet with the relative standard of GB2719-2003. The result of sensory attributes of pear vinegar assessed by Fuzzy was "accepted generally".更多还原