碧根果精油-壳聚糖-乳清分离蛋白可食膜的制备及其在碧根果仁保鲜中的研究

Preparation of pecan essential oil-chitosan-whey protein isolate edible film and its application on pecan preservation

本文首先分析了碧根果外壳的精油(pecan essential oil,PEO)组成,接着制备了含不同PEO浓度(0、0.5、1.5、2.5、3.5 mg/mL)的碧根果精油-壳聚糖-乳清分离蛋白(pecan essential oil-chitosanwhey protein isolate,PEO-CS-WPI)可食膜,并将其用于碧根果仁的保鲜。结果表明,PEO的主要成分为酯类、烷烃类、酸类、醛类、醇类、吡啶类、酚类和酮类;PEO浓度对PEO-CS-WPI厚度没有显著影响,但PEO-CS-WPI的溶胀率、a~*和b~*随着PEO浓度的增大而增大,红外光谱分析表明PEO与CS、WPI通过氢键相互作用;PEO-CS-WPI可食膜不仅有效抑制碧根果仁贮藏过程中的脂肪氧化,以及霉菌和酵母菌的生长,降低碧根果仁过氧化值和酸价的增加,延长其货架期,而且能够提高碧根果仁的总酚含量和抗氧化活性。

The composition of pecan essential oil(PEO)extracted from pecan shells was analyzed,pecan essential oil-chitosan-whey protein isolate(PEO-CS-WPI)film with different PEO concentrations(0,0.5,1.5,2.5,3.5 mg/mL)were prepared and used in the preservation of pecan.The results showed that main components of PEO were esters,alkanes,acids,aldehydes,alcohols,pyridines,phenols and ketones.The PEO concentration had no significant effect on the thickness of the PEO-CS-WPIfilm,but swelling rate,a*and b*of the PEO-CS-WPIfilm increased with PEO concentration increase.The infrared spectrum analysis showed that PEO interacted with CS and WPI through hydrogen bonding.The results of pecan storage experiments showed that PEO-CS-WPI ediblefilm not only effectively inhibited fat oxidation and mold and yeast growth of pecan,but also reduced the increase of peroxide value and acid value of pecan during storage,therefore the shelf life of pecan was prolonged.The total phenol content and antioxidant activity of pecan were increased as well.