【作者】 李秋；

【导师】 陶文沂；

【作者基本信息】 江南大学 ， 发酵工程， 2008， 硕士

【摘要】 沙棘(Hippophae rhaxnnoides)是胡颓子科沙棘属植物,其果实含有丰富的生物活性物质,具有很多保健机能。目前,多数沙棘加工企业仅限于生产沙棘油,提取黄酮,而大量的果汁除少量被利用外,由于保鲜不当变质损失。因此,我们在沙棘综合开发的基础上,对沙棘果汁发酵保健型果醋进行了实用性研究,希望为沙棘深度开发奠定技术基础。本论文以建立一种比较理想的研制保健型沙棘果醋的发酵方式为目标,对几种发酵方式的工艺进行优化,对不同发酵方式研制的沙棘果醋进行成分分析,并与沙棘果汁和国内大家公认的恒顺优质香醋进行比较。主要研究方法和结果如下:1.研究了前液态酒精-后固态醋酸(液-固)发酵的工艺条件。结果表明酒精液态发酵最佳条件为:发酵温度27℃、初始糖度15.00%、初始pH 4.0、酵母接种量12%、发酵5 d。醋酸固态发酵的最佳条件为:初始酒度7.00%,麸皮与稻壳比为5:1,醋酸菌接种量10%,醋醅含水量控制在60%~64%,发酵周期为14 d。2.研究了大曲封缸静置发酵及液-液通风发酵的工艺条件。结果表明大曲发酵最佳条件为:初始pH 4.0,初始糖度11.00%,大曲接种量25%,果渣接入量0%,发酵周期约3个月。对试验影响最大的是大曲接种量,其次是初始pH、初始糖度,果渣的介入对发酵不利,这主要是由于果渣经过了CO2超临界萃取和乙醇萃取。液-液摇床发酵最佳条件为:醋酸菌接种量10%,初始酒度7.00%,转速160 r/min,温度30℃,相对装液量1/5(100 mL),发酵时间84 h;液-液深层发酵最佳条件为:接种量10%,发酵温度32~34℃,最佳通气量为前期:(17 h)1:0.07 (v/v)/min,中期:1:0.1 (v/v)/min,后期:(36 h后)1:0.07 (v/v)/min,罐压0.3 kg/cm~2,发酵时间为72 h。3.对不同发酵方式研制的沙棘果醋进行成分分析,并与原果汁及恒顺优质香醋比较。结果表明沙棘果醋中香气成分种类少于恒顺香醋,液-固发酵醋中香气成分种类多于其他方式研制的果醋,在大曲发酵醋中发现了其他醋中没有的物质—川楝素。只有大曲发酵醋、液-固发酵醋和恒顺醋中含有川穹嗪;不同沙棘醋中,液-固发酵醋中Vc、多肽及总蛋白的含量最高,但多肽略低于恒顺醋,而多酚和总黄酮的含量低于大曲醋,高于恒顺醋,液-液发酵醋中这些物质含量最低。对DPPH自由基清除活性的比较为:液-固发酵醋>恒顺醋>大曲发酵醋>果汁>液-液深层发酵醋>液-液摇瓶发酵醋。总氨基酸的含量比较为:恒顺醋>大曲发酵醋>液-固发酵醋>果汁>液-液摇瓶发酵醋>液-液深层发酵醋。由此,最终确定了研制沙棘果醋比较理想的方法是液-固发酵法。更多还原

【Abstract】 Hippophae rhaxnnoides is a plant of the elaeagnaceae sea-buckthorn. The fruits are rich in bioactive substances which have many health functions. Recently, those Hippophae rhaxnnoides-processing enterprises only restricted in the production of sea-buckthorn oil and the extraction of flavanone, the massive fruit juice was deteriorated because of improper freshness-maintaining methods, few was actually used. So, based on the comprehensive development of Hippophae rhaxnnoides, we carried out the practicability research on the fermentation of fruit vinegar with the sea-buckthorn juice, hoped that could establish the technological supports for the development of Hippophae rhaxnnoides.The goal of this paper is mainly to establish a quite ideal fermentation which produces health care style Hippophae rhaxnnoides vinegar, to work on the optimization of several kinds of fermentation processes, to make analysis of the further ingredient in the vinegars developed by different fermentation processes, and to make comparison on flavour and healthy components with the original fruit juice and Hengshun aromatic vinegar which was commonly recognized in Domestic. The main research techniques and the results are as follows:1.The technical conditions of liquid alcohol-solid vinegar fermentation(L-S) were studied. The result showed that the optimum conditions for liquid state alcohol ferment method were at 27℃, initial sugar 15.00%, initial pH 4.0, yeast inoculation ratio 12% for 5 d. And for solid state vinegar ferment method were at initial alcohol 7.00%, the ratio of bran to rice shell 5:1, with inoculation of acetobacteria 10% for 14 d.2.The technical conditions of koji jar-sealing fermentation(KJS) and liquid alcohol-liquid vinegar fermentation(L-L) were studied. The result showed that the optimum conditions for KJS were initial pH 4.0, initial sugar 11.00%, koji inoculation was 25% in quantity, marc was 0% in quantity, the fermentation time was approximately 3 months. The koji inoculation is the most important influencing factor to the result, followed by initial pH and initial sugar. The marc is disadvantageous to the fermentation, mainly because the marc had been extracted at the CO2 supercritical and ethyl alcohol. The optimum conditions for L-L shaking fermentation(L-Lsh) were inoculation of acetobacteria 10%, initial alcohol 7.00%, shaking speed 160 r/min with relative liquid volume 1/5(100 mL) at 30℃for 84 h. The optimum conditions for L-L submerged fermentation(L-Lsu) were inoculation of acetobacteria 10% at 32~34℃. The best quantity of ventilation in the earlier period(17 h) was 1:0.07(v/v)/min, intermediate stage was 1:0.1(v/v)/min, later period (after 36 h) was 1:0.07(v/v)/min, pressure at 0.3 kg/cm~2, and fermentation for 72 h.3.The ingredients of Hippophae rhaxnnoides vinegar produced by different fermentation processes were analysed, and compared with the original fruit juice and Hengshun aromatic vinegar. The result showed that there were fewer kinds of fragrance ingredients in Hippophae rhaxnnoides vinegar compared with Hengshun vinegar, and more kinds of fragrance ingredients in the L-S vinegar than other vinegars produced by different fermentation processes. In KJS vinegar, Toosendaninin had been discovered which wasn’t involved in other vinegars. Tetramethylpyrazine was discovered only in KJS vinegar, L-S vinegar and Hengshun vinegar. Among different Hippophae rhaxnnoides vinegars, the content of Vc, polypeptide and protein in L-S vinegar are highest, but are lower than Hengshun vinegar, the contents of polyphenol and total flavones are lower than KJS vinegar, but higher than Hengshun vinegar, the contents of these materials in the vinegar produced by L-L are permanently lowest. The result of comparison of the DPPH radical scavenging activity was: L-S vinegar > Hengshun vinegar > KJS vinegar > fruit juice > L-Lsu vinegar > L-Lsh vinegar. The result of comparison of the total amino acid content was: Hengshun vinegar > KJS vinegar > L-S vinegar > fruit juice > L-Lsh vinegar > L-Lsu vinegar. At last, the liquid-solid fermentation(L-S)was established for the quite ideal method to produce Hippophae rhaxnnoides vinegar.更多还原