该文以不同物理方法提取的莼菜体外胶为主原料,探讨体外胶本身的物理性能以及生物学特性。结合超声处理研究莼菜体外胶质构性、流变特性、化学物质含量以及抑制酶活性情况,采用GC-MS测定体外胶多糖的单糖组成。结果表明,当超声能量密度为4 800 J/g时,体外胶的分离率最高为(78.97±3.83)％。经超声处理后的体外胶的黏度显著降低,在高扫描频率下超声处理会显著增加体外胶的损耗模量(G″),从而增加它的黏性。体外胶含有丰富的总糖(524.4~552.8 mg/g)和总多酚(208.3~228.5 mg GAE/g),并具有α-葡萄糖苷酶和α-淀粉酶抑制活性。GC-MS分析结果表明,体外胶多糖含有较高含量的半乳糖(41.79％)和木糖(18.72％),且含有较少含量的甘露糖(4.29％),鼠李糖(7.13％),阿拉伯糖(1.02％)和葡萄糖(4.55％)。超声处理不仅会降低体外胶的硬度、弹性、内聚性和黏附性,还有助于体外胶的分离,可以很好地保持体外胶的植物化学物质、抗氧化活性、降血糖活性。
The effect of several physical methods on the separation rate of mucilage gel from Brasenia schreberi was investigated. In addition, the effects of ultrasound treatment on the texture characteristics, rheological properties, chemical content and inhibitory enzyme activity of mucilage gel in different drying methods were also investigated. The monosaccharide composition of mucilage gel polysaccharide was determined by GC-MS. The highest yield ( (78.97±3.83)%) of mucilage gel was obtained by ultrasound treatment with an energy density of 4 800 J/g. The viscosity of ultrasound-treated mucilage gel samples decreased significantly and exhibited near-Newtonian flow behaviour. Furthermore, the ultrasound treatment at high scanning frequency significantly increased the loss modulus (G & quot;) of the mucilage gel, and increased its viscosity. The mucilage gel contained a high content of total carbohydrate (524.4-552.8 mg/g) and polyphenols (208.3-228.5 mg GAE/g). Mucilage gel also had a certain inhibitory effect on α-glucosidase and α-amylase activity. The monosaccharide composition of mucilage gel polysaccharide was rich in galactose (41.79%) and xylose (18.72%), while mannose (4.29%), rhamnose (7.13%), arabinose (1.02%), glucose (4.55%) were also identified as minor monosaccharide. Therefore, ultrasound treatment contributed to the separation of mucilage gel and could remarkably change the physical properties of gel, while kindly preserved photochemicals and their bioactivities.
[1] 刘永琼, 余世鑫, 桂昭明,等. 莼菜的研究进展[J]. 汉化工学院学报, 1997, (19): 15-18.
[2] 王倩, 莼菜多糖的提取及其功能特性的研究[D].无锡:江南大学,2009.
[3] 周毅峰, 吴永尧, 唐巧玉,等. 莼菜体外胶质分离及组成成分的初步分析[J]. 食品与发酵工业, 2005, 31(4): 150-153.
[4] SESHADRI R, WEISS J,HOLBERTG J,et al. Ultrasonic processing influences rheological and optical properties of high-methoxyl pectin dispersions [J]. Food Hydrocolloids, 2003, 17(2):191-197.
[5] RASOULI M, OSTOVAR-RAVARI A, SHOKRI-AFRA H. Characterization and improvement of phenol-sulfuric acid microassay for glucose-based glycogen [J]. European Review for Medical and Pharmacological Sciences, 2014, 18(14): 2 020-2 024.
[6] GB 5009.7—2016 食品中还原糖的测定[S]. 北京:中国标准出版社, 2016.
[7] GB5009.5—2016 食品中蛋白质的测定[S]. 北京:中国标准出版社, 2016.
[8] QURESHI M N, STECHER G, BONN G K. Determination of total polyphenolic compounds and flavonoids in Juglans regia leaves [J]. Pakistan Journal of Pharmaceutical Sciences, 2014, 27(4):865-869.
[9] SN/T 4592—2016 出口食品中总黄酮的测定[S]. 北京:中国标准出版社, 2016.
[10] REZANKA T, SIGLER K. Structural analysis of a polysaccharide from Chlorella kessleri by means of gas chromatography-mass spectrometry of its saccharide alditols [J]. Folia Microbiologica, 2007, 52(3): 246-252.
[11] WANG Q, SUN Y, YANG B, et al. Optimization of polysaccharides extraction from seeds of Pharbitis nil and its anti-oxidant activity [J]. Carbohydrate Polymers, 2014, 102: 460-466.
[12] NINAGAWA T, EGUCHI A, KAWAMURA Y, et al. A study on ice crystal formation behavior at intracellular freezing of plant cells using a high-speed camera [J]. Cryobiology, 2016, 73(1): 20-29.
[13] KIM H, WANG Q, SHOEMAKER C F, et al. Polysaccharide gel coating of the leaves of Brasenia schreberi lowers plasma cholesterol in hamsters [J]. Journal of Traditional and Complementary Medicine, 2015, 5(1): 56-61.
[14] KAKUTA M, MISAKI A. Polysaccharide of “Junsai (Brasenia schreberiJF Gmel)” Mucilage: Constitution and linkage analysis[J]. Journal of Agricultural and Food Chemistry, 1979, 43(5): 993-1 005.
[15] ABID M, RENARD C M G C. Yield and composition of pectin extracted from Tunisian pomegranate peel [J]. International Journal of Biological Macromolecules, 2016, 93: 186-194.
[16] ZHAO L, ZHAO G, CHEN F, et al. Different effects of microwave and ultrasound on the stability of (all-E)-astaxanthin [J]. Journal of Agricultural and Food Chemistry, 2006, 54(21):8 346-8 351.
[17] JAMBRAK A R, HERCEG Z,SUBARIC′ D,et al. Ultrasound effect on physical properties of corn starch [J]. Carbohydrate Polymers, 2010, 79(1):91-100.
[18] ZHONG K, ZHANG Q, TONG L, et al. Molecular weight degradation and rheological properties of schizophyllan under ultrasonic treatment [J]. Ultrasonics Sonochemistry, 2015, 23:75-80.
[19] CHEN S, CHEN H, TIAN J, et al. Chemical modification, antioxidant and α-amylase inhibitory activities of corn silk polysaccharides [J]. Carbohydrate Polymers, 2013, 98(1):428-437.
