谷胱甘肽添加对蓝莓果酱品质的影响

Effects of Glutathione Addition on the Quality of Blueberry Jam

为优化果酱加工工艺,使用适量的谷胱甘肽替代抗坏血酸(维生素C)制备蓝莓果酱,测定其加工过程中果酱持水力、色泽、总酚、花青素、抗氧化性及流变特性的变化。结果表明,与添加维生素C的对照组相比,谷胱甘肽的添加可减缓持水力、总酚及花色苷含量的下降程度。同时,显著提升样品的亮度L~*值(P<0.05),保护蓝莓果酱的色泽。谷胱甘肽的添加也可增强蓝莓果酱成品对1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl,DPPH)自由基、羟基自由基和2,2-联氨-双-3-乙基苯并噻唑啉-6-磺酸(2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid,ABTS))阳离子自由基的清除能力(P<0.05),使蓝莓果酱表现出更强的抗氧化能力。流变学结果显示,蓝莓果酱为剪切稀化的假塑性流体,储能模量(G′)始终大于相应的损耗模量(G″),表现出以弹性为主的黏弹体特征。谷胱甘肽添加组的黏度值、G′值和G″均高于相应的对照组(P<0.05),表明谷胱甘肽的添加可增加蓝莓果酱的黏性和流体性质,使其具有更好的剪切稳定性和黏弹性。综上,谷胱甘肽的添加能较好地改善果酱品质特性,可为新型高端果酱产品的开发提供理论参考。

In order to optimize the processing technology of jam,an appropriate amount of glutathione was used to replace ascorbic acid(Vitamin C)for the preparation of blueberry jam,the changes in water holding capacity,color,total phenols,anthocyanins,antioxidant properties,and rheological characteristics of jam during processing were determined.The results showed that compared with the control group with added Vc,the addition of glutathione could slow down the decrease in water holding capacity,total phenols,and anthocyanin content.Additionally,it significantly increased the brightness L~*value of the samples(P<0.05),protecting the color of blueberry jam.As well,the ability of the blueberry jam to remove 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical,hydroxyl radical and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)(ABTS)radical cation were enhanced with the addition of glutathione,showing a stronger antioxidant ability.The rheology results showed that blueberry jam exhibits a shear-thinning pseudoplastic fluid behavior,with the storage modulus(G')always greater than the corresponding loss modulus(G''),indicating a viscoelastic character dominated by elasticity.The viscosity,G'and G"values of the glutathione addition group were higher than those of the corresponding control group(P<0.05),demonstrating that the addition of glutathione increases the viscosity as well as fluid properties of blueberry jam,enabling it a better shear stability and viscoelasticity.In conclusion,adding glutathione can preferably ameliorate the quality characteristics of jams,thus providing theoretical references for developing new high-end jam products.