Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a ch...Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a challenge for their marketing. The potential for low temperature conditioning (LTC) treatment to inhibit peel browning and improve quality of Huangguan pears in storage and shelf life was investigated. Pears were treated at 8℃ - 9℃ for 1, 3, 6 and 9 d, respectively, physiological indexes, including peel and core browning, core breakdown, malondialdehyde (MDA) content and ethanol content were determined and quality in storage period and shelf life was evaluated in this paper. LTC treatment alleviated peel browning and core browning either in storage or shelf life remarkably;it also delayed the decline of firmness, total soluble solids and titratable acidity in storage to some extent, inhibited ethanol and MDA content both in storage and shelf life effectively and maintained juiciness and crispness of pear fruit in shelf life. These results showed that LTC can serve as an important tool for the regulation of Huangguan pears external and internal quality in storage and shelf life with economic benefits and LTC treatment for 6 d was the optimum condition in the present study.展开更多
采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析皇冠梨中梨皮、梨肉、梨汁中的香气成分。结果表明:共鉴定出香气成分56种,3个样...采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析皇冠梨中梨皮、梨肉、梨汁中的香气成分。结果表明:共鉴定出香气成分56种,3个样品中均含有酯类物质,其中果皮中最多,果肉居中,果汁最少,分别占香气物质的27.21%、9.63%、0.19%。除此之外还含有正己醛、反式-2-己烯醛、壬醛,且总量分别占果肉样及果汁样中香气物质的4.50%、52.20%,甲基庚烯酮占果皮样及果肉样中香气物质的0.42%、1.48%。其中反式-2-己烯醛具有新鲜的绿叶香味;甲基庚烯酮具有水果香气和新鲜清香香气;壬醛具有玫瑰、柑橘等香气、青味、油脂味;癸醛稀薄时具有果味香,使得皇冠梨具备了独特的怡人风味。此外,皇冠梨果皮中香气成分较为丰富,共检测出33种,其中特有成分14余种,因此,建议在加工皇冠梨果汁、果脯、罐头等产品时,尽量保留果皮,以保留产品独特香气。皇冠梨肉样中检测出香气成分16种,皇冠梨汁样中检测出的香气成分18种,其中特有成分共近20种,适宜加工生产果汁、罐头产品。展开更多
文摘Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a challenge for their marketing. The potential for low temperature conditioning (LTC) treatment to inhibit peel browning and improve quality of Huangguan pears in storage and shelf life was investigated. Pears were treated at 8℃ - 9℃ for 1, 3, 6 and 9 d, respectively, physiological indexes, including peel and core browning, core breakdown, malondialdehyde (MDA) content and ethanol content were determined and quality in storage period and shelf life was evaluated in this paper. LTC treatment alleviated peel browning and core browning either in storage or shelf life remarkably;it also delayed the decline of firmness, total soluble solids and titratable acidity in storage to some extent, inhibited ethanol and MDA content both in storage and shelf life effectively and maintained juiciness and crispness of pear fruit in shelf life. These results showed that LTC can serve as an important tool for the regulation of Huangguan pears external and internal quality in storage and shelf life with economic benefits and LTC treatment for 6 d was the optimum condition in the present study.
文摘选用紫薯、黄冠梨作为发酵原料,利用酵母菌和醋酸菌先后进行酒精和醋酸发酵制备复合果醋。以产酸量作为评价指标,针对醋酸发酵时间、发酵温度、乙醇添加量、初始p H等参数设置单因素试验,采用正交优化,确定醋酸发酵阶段最佳工艺条件。结果表明,各因素对紫薯梨复合果醋产酸量影响程度为:装液量>接种量>乙醇加入量>发酵温度。得到的最佳条件为:醋酸菌接种量12%,装液量50 m L,乙醇加入量3%,发酵温度30℃。根据上述最优发酵条件,产酸量可达42.03 g/L。
文摘采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析皇冠梨中梨皮、梨肉、梨汁中的香气成分。结果表明:共鉴定出香气成分56种,3个样品中均含有酯类物质,其中果皮中最多,果肉居中,果汁最少,分别占香气物质的27.21%、9.63%、0.19%。除此之外还含有正己醛、反式-2-己烯醛、壬醛,且总量分别占果肉样及果汁样中香气物质的4.50%、52.20%,甲基庚烯酮占果皮样及果肉样中香气物质的0.42%、1.48%。其中反式-2-己烯醛具有新鲜的绿叶香味;甲基庚烯酮具有水果香气和新鲜清香香气;壬醛具有玫瑰、柑橘等香气、青味、油脂味;癸醛稀薄时具有果味香,使得皇冠梨具备了独特的怡人风味。此外,皇冠梨果皮中香气成分较为丰富,共检测出33种,其中特有成分14余种,因此,建议在加工皇冠梨果汁、果脯、罐头等产品时,尽量保留果皮,以保留产品独特香气。皇冠梨肉样中检测出香气成分16种,皇冠梨汁样中检测出的香气成分18种,其中特有成分共近20种,适宜加工生产果汁、罐头产品。
