中国农业科学 ›› 2022, Vol. 55 ›› Issue (12): 2398-2412.doi: 10.3864/j.issn.0578-1752.2022.12.011

• 园艺 • 上一篇    下一篇

替代柑橘聚乙烯薄膜单果套袋的涂膜剂研发及保鲜效果评价

邹运乾,林子桢,许让伟(),程运江()   

  1. 华中农业大学园艺林学学院/国家柑橘保鲜技术研发专业中心/农业农村部园艺作物生物学与种质创制(果树)重点实验室/园艺植物生物学教育部 重点实验室,武汉 430070
  • 收稿日期:2021-10-13 接受日期:2021-12-14 出版日期:2022-06-16 发布日期:2022-06-23
  • 通讯作者: 许让伟,程运江
  • 基金资助:
    云南省院士专家工作站(202005AF150080)

Development and Evaluation of a Coating Substitute for Individual Polyethylene Film Packaging of Citrus Fruit

ZOU YunQian,LIN ZiZhen,XU RangWei(),CHENG YunJiang()   

  1. College of Horticulture and Forestry Science, Huazhong Agricultural University/National R&D Center for Citrus Preservation, Key Laboratory of Horticultural Crop Biology and Germplasm Genetic Improvement (Fruit Crops), Ministry of Agriculture and Rural Affairs/Key Laboratory of Horticultural Plant Biology, Ministry of Education, Wuhan 430070
  • Received:2021-10-13 Accepted:2021-12-14 Online:2022-06-16 Published:2022-06-23
  • Contact: RangWei XU,YunJiang CHENG

摘要:

【背景】 聚乙烯薄膜单果套袋是目前我国最为常用的柑橘贮藏期保鲜方式,近50年来在全国大范围应用。近年来聚乙烯薄膜果袋因使用后回收难带来的环境污染问题引起全社会广泛关注,且由于柑橘单果套袋主要依赖手工完成,导致劳动力日益紧缺、生产成本逐年上升等问题日益凸显。因此,研发一种能替代聚乙烯薄膜的新型涂膜材料,实现柑橘保鲜生产向全程机械化转型是产业的重大需求。【目的】 研发以小烛树蜡及蜂蜡为基础的“BC”(Beeswax-Candelilla Wax Coating)涂膜剂配方,并用于处理温州蜜柑果实,评价其保鲜效果以及替代聚乙烯薄膜单果套袋的可行性。【方法】 选择最优比小烛树蜡、蜂蜡和甘油组合涂膜剂,以成熟‘尾张’温州蜜柑果实为试验材料,进行套袋或涂膜处理。对处理后的果实在不同时间节点检测以下指标:果实失重率、硬度、色差、果汁总可溶性固形物(TSS)/可滴定酸(TA)含量、果皮总酚总黄酮含量、呼吸强度、果实内部气体成分和异味物质含量,并用气相质谱仪检测不同处理果皮初生代谢物含量。扫描电镜观察处理后果面蜡质形态;同时对光泽度、异味、风味、出汁量、甜度、酸度和总体满意度等指标进行感官评价。【结果】 BC涂膜剂处理温州蜜柑果实常温贮藏28 d后,果实失重率从22.62%显著降低到3.83%;同时延缓硬度与色差值的变化,延缓果实内部TSS和TA含量变化,提高果皮总酚、总黄酮及初生代谢物含量。果实内部CO2浓度适度升高,呼吸强度从43.36 mL·kg-1·h-1显著降低到16.75 mL·kg-1·h-1;较对照处理而言,BC处理还增强了果实感官品质,总体满意度从3.09提升至3.69。除异味物质、呼吸强度外,其他各项指标检测结果均表明BC与套袋处理无显著性差异,但BC处理的果实中乙醇含量(777.9 mg·L-1)显著低于人类感知阈值水平(1 500 mg·L-1)及商业涂膜剂处理后的浓度(2 021.2 mg·L-1)。【结论】 BC涂膜剂保水性能良好,涂膜处理后与套袋果实相比,果实的内部品质、外观品质以及测定的各项生化指标均无显著性差异。而且涂膜处理与果实采后加工分选线兼容性好,可实现在线打蜡处理,生产效率高,生产用工少。综上表明BC涂膜具备替代套袋保鲜作用。

关键词: 柑橘, 蜂蜡, 小烛树蜡, 套袋, 采后贮藏

Abstract:

【Background】 Individual polyethylene film packaging is the most popular way to maintain citrus quality during storage in China. This method has been applied nationwidely since the 1970s. In recent years, the environmental pollution problems caused by the use of polyethylene films aroused caused concerns of the public. Besides, the conflict between labor-intensive property of individual polyethylene film treatment and the shrinking workforce as well as increasing labor costs in China makes it urgent to develop a substitute of polyethylene film to achieve mechanization in citrus postharvest preservation industry. 【Objective】 A new formula of coating called “BC” (Beeswax-Candelilla Wax Coating) based on beeswax and candelilla wax was developed, and its potential to replace polyethylene film and the effects on the improvement of postharvest quality and the extension of shelf life of satsuma mandarin were evaluated. 【Method】 The optimal formulas among different groups were selected to treat satsuma mandarin fruit. Satsuma mandarin fruit were used as experimental material for the packaging (TD) or coating treatment. The indicators were tested at different time points during storage, including the rate of weight loss, firmness, color index, TSS (Total soluble solid)/TA (Titratable acid), total phenol and flavonoid contents in the peels, respiration rate, internal CO2 concentration of fruits and the content of off-flavor substances. The primary metabolits contents in the peel were tested by GC-MS (Gas chromatography mass spectrometry). The microstructure of fruit surface was examined by SEM (Scanning Electronic Microscopy). Besides, the glossiness, off-flavor, flavor, juiciness, sweetness, acidity and overall satisfaction of satsuma mandarin were assessed by sensory evaluation. 【Result】 The weight loss of “BC” coated fruit sharply dropped from 22.62% to 3.83% after one month of storage at 23-25℃. “BC” coating delayed changes in firmness, color deterioration, TSS and TA loss, and increase in TPC, TFC and primary metabolites contents. The increased internal CO2 levels led to a striking decrease in respiration intensity from 43.36 mL·kg-1·h-1 to 16.75 mL·kg-1·h-1. “BC” coating also significantly improved the sensory quality compared with the control treatment, with the score increasing from 3.09 to 3.69. No differences (P<0.05) were found between TD and “BC” groups except for the content of off-flavor substances and respiration rate. The ethanol concentration of “BC” coating group (777.9 mg·L-1) was significantly lower than human perception threshold (1 500 mg·L-1) and that of commercial wax treatment (2 021.2 mg·L-1). 【Conclusion】 The optimal formula of “BC” coating could enhance water retention capacity of satsuma mandarins. No significant differences were found in internal quality, appearance and other biochemical indicators between the polyethylene film packaged fruit and those from “BC” coating treatment. The advantages such as high productivity, low cost and less environmental pollution in modern postharvest handling of fruits and vegetables made “BC” coating a promising alternative to polyethylene films.

Key words: citrus, beeswax, candelilla wax, packaging, postharvest storage