中国农业科学 ›› 2016, Vol. 49 ›› Issue (10): 1979-1989.doi: 10.3864/j.issn.0578-1752.2016.10.013

• 贮藏·保鲜·加工 • 上一篇    下一篇

不同乳酸菌发酵对桂圆肉中酚类物质及抗氧化活性的影响

赖 婷1,2,刘 磊2,张名位2,张瑞芬2,张 雁2,魏振承2,邓媛元2   

  1. 1福建农林大学食品科学学院,福州 350000
    2广东省农业科学院蚕业与农产品加工研究所/农业部功能食品重点实验室/广东省农产品加工重点实验室,广州 510610
  • 收稿日期:2015-10-13 出版日期:2016-05-16 发布日期:2016-05-16
  • 通讯作者: 张名位,E-mail:mwzhh@vip.tom.com
  • 作者简介:赖婷,E-mail:clt.199@163.com
  • 基金资助:
    国家自然科学青年基金(31301459)、国家“十二五”科技支撑计划(2012BAD33B10)、广东省自然科学基金(2014A030313568)、广州市珠江科技新星专项(201506010028)、广州市对外合作项目(2013J4500023)、广州市民生科技重大专项(201300000077)

Effect of Lactic Acid Bacteria Fermentation on Phenolic Profiles and Antioxidant Activity of Dried Longan Flesh

LAI Ting1,2, LIU Lei2, ZHANG Ming-wei2, ZHANG Rui-fen2, ZHANG Yan2, WEI Zhen-cheng2, DENG Yuan-yuan2   

  1. 1Food Science College, Fujian Agriculture and Forestry University, Fuzhou 350000
    2Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610
  • Received:2015-10-13 Online:2016-05-16 Published:2016-05-16

摘要: 【目的】比较不同乳酸菌种发酵对桂圆肉(干制的龙眼果肉)中游离态、结合态酚类物质含量和单体酚组成及其抗氧化活性的影响,为开发营养保健的乳酸菌发酵龙眼新产品提供参考。【方法】将桂圆肉打浆(料水比为1﹕1.5)后作为发酵基质,进行高温湿热灭菌,再分别接入7种不同乳酸菌(植物乳杆菌、嗜酸乳杆菌、戊糖片球菌、明串珠菌、保加利亚乳杆菌、德氏乳杆菌保加利亚亚种和干酪乳杆菌,菌浓度:8.0—9.0 lg CFU/mL),接种量为1%,在30℃下静置发酵48 h(pH 4.0—4.2),然后对发酵前后桂圆肉中游离态和结合态总酚、总黄酮含量的变化进行分析,采用高效液相色谱法分析其单体酚类的组成及含量的变化,采用铁离子还原能力(ferric reducing abi1ity of plasma,FRAP)和氧自由基吸收能力(oxygen radical absorption capacity,ORAC)两种方法评价其体外抗氧化能力差异。【结果】7种乳酸菌发酵均能不同程度增加桂圆肉中游离态总酚和总黄酮含量,降低结合态总酚和总黄酮含量。与发酵前相比,发酵后桂圆肉游离态总酚含量增加0.4%—11.9%,结合态总酚含量下降14.4%—41.4%;游离态总黄酮含量增加2.8%—19.6%,结合态总黄酮含量下降19.6%—70.6%。但不同菌种对其影响存在差异,其中植物乳杆菌释放桂圆肉中结合态酚类物质的能力最强,使游离酚含量增加11.9%,结合态酚含量下降41.4%,游离态总黄酮增加19.6%,结合态总黄酮下降70.6%。不同乳酸菌发酵对桂圆肉中单体酚(没食子酸、丁香酸、表儿茶素、高儿茶酚、原儿茶酸、对香豆酸和异槲皮苷)含量影响亦存在显著差异(P<0.05),其中发酵后的游离态的没食子酸和高儿茶酚含量分别增加8.6%—69.8%和0.4%—29.5%,结合态的没食子酸和高儿茶酚含量分别下降80.0%—88.3%和45.6%—73.9%。而乳酸菌发酵后,桂圆肉游离态FRAP和ORAC抗氧化能力与发酵前相比也有显著提高(P<0.05),其中植物乳杆菌发酵后,游离态FRAP和ORAC抗氧化能力分别提高11.8%和59.1%。【结论】乳酸菌发酵能提高桂圆肉中游离态酚类物质含量,降低结合态酚类物质含量,同时提高其抗氧化能力。植物乳杆菌在发酵桂圆肉的过程中,其释放结合态酚类物质的能力明显优于其他乳酸菌,其发酵后桂圆肉的抗氧化能力也有明显提高。

关键词: 乳酸菌, 桂圆肉, 总酚, 总黄酮, 抗氧化活性

Abstract: 【Objective】 The effect of lactic acid bacteria fermentation on free and bound phenolics and flavonoids and on antioxidant activity of dried longan flesh was investigated, with the purpose of giving some technical guidance for the deep processing of dried longan, and the development of new nutrition and health products fermented by lactic acid bacteria. 【Method】The culture medium was longan fruit pulp (the dried longan flesh: water=1:1.5), which then was inoculated by seven strains (Lactobacillus acidophilus GIM 1.731, Leuconostoc mesenteroides GIM 1.473, Lactobacillus casei GIM 1.411, Pediococcus pentosaceus GIM 1.428, Lactobacillus plantarum subsp. plantarum GIM 1.380, Lactobacillus delbrueckii subsp. lactis GIM 1.407, Lactobacillus bulgaricus GIM 1.155, bacteria concentration: 8.0-9.0 lg CFU/mL) with 1% at 37℃ for 48 hours. The contents of free and bound phenolics and flavonoids in dried longan flesh were determined. A high performance liquid chromatography (HPLC) method was used to measure the compositions and contents of phenolics in dried longan flesh. The antioxidant activity was analyzed using the ferric reducing ability of plasma (FRAP) and Oxygen Radical Absorption Capacity (ORAC). 【Result】 Seven lactic acid bacterias can increase, to different extents, the content of free phenolics and flavonoids in dried longan flesh (P<0.05), and reduce the content of bound phenolics and flavonoids (P<0.05). Compared to the no fermentation group, the content of free phenolics increased by 0.4%-11.9%, the content of bound phenolics decreased by 14.4%-41.4%; the content of free flavonoids increased 2.8%-19.6%, and the content of flavonoids decreased by 19.6%-70.6%. Lactobacillus plantarum subsp. plantarum GIM 1.380 had more advantages than other lactic acid bacteria on the ability of releasing bound phenolics, The content of free phenolics increased by 11.9%, the content of bound phenolics decreased by 41.4%, the content of free flavonoids increased by 19.6%, and the content of flavonoids decreased by 70.6%. Different lactic acid bacteria had different influence on phenolics compositions in dried longan flesh (gallic acid, syringic acid, (-)-Epicatechin, 4-methylcatechol, protocatechuic acid, p-coumaric acid, and isoquercetin). Compared to the no fermentation group, the content of free gallic acid and 4-methylcatechol were increased by 8.6%-69.8% and 0.4%-29.5%, and the content of bound gallic acid, vanillic acid and 4-methylcatechol were decreased by 80.0%-88.3% and 45.6%-73.9%. After fermentation, the free FRAP value and ORAC value were obviously increased (P<0.05), compared with the no fermentation group. 【Conclusion】 Lactic acid bacteria fermentation could increase the content of free phenolics in dried longan flesh, and reduce the content of bound phenolics, as well as improve its free antioxidant activity. Different lactic acid bacteria fermentations had differently effects on the total phenolic contents and antioxidant capacity and phenolic compositions in dried longan flesh. The result indicated that Lactobacillus plantarum subsp. plantarum GIM 1.380 had more advantages than the other lactic acid bacteria in the ability of releasing bound phenolics and improving antioxidant ability.

Key words: lactic acid bacteria, dried longan flesh, phenolics, flavonoids, antioxidant activity