低強度UV-A光循環(huán)照射結(jié)合ε-聚賴氨酸處理對4 ℃下鮮切菠菜保鮮效果的研究

郁杰，張雨宸，謝晶

1(上海海洋大學 食品學院，上海，201306)2(農(nóng)業(yè)農(nóng)村部冷庫及制冷設備質(zhì)量監(jiān)督檢驗測試中心(上海)，上海，201306)3(上海冷鏈裝備性能與節(jié)能評價專業(yè)技術(shù)服務平臺，上海，201306)4(食品科學與工程國家級實驗教學示范中心(上海海洋大學)，上海，201306)

Theeffectofcyclicirradiationoflow-intensityUV-Acombinedwithε-Polylysineonthepreservationoffresh-cutspinachat4℃

YU Jie1，3,ZHANG Yuchen1，3,XIE Jing1，2，3，4*

1(College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China)2(Quality Supervision, Inspection and Testing Center for Cold Storage and Refrigeration Equipment(Shanghai), Ministry of Agriculture, Shanghai 201306, China)3(Shanghai Professional Technology Service Platformon Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China)4(National Experimental Teaching Demonstration Center for Food Science and Engineering(Shanghai Ocean University), Shanghai 201306, China)

ABSTRACTIn order to investigate the effect of UV-A illumination combined withε-polylysine on fresh-cut spinach, the optimum preservation concentration ofε-polylysine solution was determined by sensory indicators, water loss, microbiological indicators, antioxidant enzyme indicators and nutritional indicators. The results indicated that 0.05 g/Lε-polylysine solution had the best preservation effects on fresh-cut spinach combined with UV-A (0.588 kJ/m2) illumination, which was conducted at an interval of 8 h. And it can extend shelf life of spinach to 12 d. 0.02 g/Lε-polylysine solution treatment could extend shelf life of spinach to 10 d with the radiation of UV-A (0.588 kJ/m2), which was conducted at an interval of 8 h. However, 0.08 g/Lε-polylysine solution showed no obvious preservation effect on spinach with the radiation of UV-A (0.588 kJ/m2), which was conducted at an interval of 8 h. In conclusion, appropriate intensity UV-A light combined withε-polylysine solution could not only slow down the growth of spoilage bacteria but also maintain the good antioxidant properties of spinach. It could provide a new development direction on the preservation of spinach for supermarkets, and attention should also be paid to the appropriate dosage in practical application.

Keywordsfresh-cut spinach; UV-A lillumination;ε-polylysine; compoumd preservation; antioxidant activity

菠菜是一種常見的可食用蔬菜，其葉片和莖為主要食用部分，人們常常將其鮮切后進行烹飪或置于4 ℃下貯藏，其因膳食纖維豐富、營養(yǎng)全面受到不同年齡人群的青睞[1]，但鮮切后的菠菜易發(fā)生汁液流失且愈傷呼吸劇烈[2]，同時菠菜鮮切部分易受到腐敗菌侵染，一旦微生物進入植物機體內(nèi)部會加快作物腐敗[3]，這些特點都加劇了鮮切菠菜相關(guān)代謝酶的降解進程及微生物對其的侵染，因此應探尋適宜的保鮮方式，提高菠菜的商品價值。

紫外線波長介于320～400 nm的光被稱長波紫外線，是紫外輻射中危害最小的部分[4]，相比UV-B、UV-C能量較低，處理葉菜類作物較為溫和，同時UV-A光照對植物抗氧化能力有一定程度的強化作用。SURJADINATA等[5]的研究中指出，通過UV-A光照處理不僅可以顯著提升阿魏酸、綠原酸、異香豆素等酚類物質(zhì)的含量，還對超氧化物歧化酶(superoxide dismutase，SOD)、過氧化物酶(peroxidase，POD)等氧化代謝酶等活性有一定的增強作用。在可推廣性上，目前市場上大部分UV-A燈管材質(zhì)為LED燈珠，具有波長穩(wěn)定、壽命長、產(chǎn)熱小、造價低廉等優(yōu)勢，具有極大的應用潛力，郁杰等[6]將UV-A光應用于鮮切菠菜，其結(jié)果表明,在420 s(1.764 kJ/m2)的照射條件下，可將鮮切菠菜貨架期延長至10 d，UV-A光照能夠顯著提升鮮切菠菜的抗氧化能力，延緩衰老，但采后葉菜本身極易失水，因此應選擇適宜的光照強度和頻率以及其他輔助手段，避免葉菜失水。……