repeated application of dynamic controlled atmospheres reduced superficial scald incidence in ‘granny smith’ apples
动态控制气氛的重复应用减少了granny smith苹果的表面烫伤发生率
asanda mditshwa ，olaniyi amos fawole，filicity vries，kobusvan der merwe ，elke crouch，umezuruike linus opar
a b s t r a c t
this study investigated the influence of repeated dynamic controlled atmosphere (dca) application to control superficial scald of ‘granny smith’ apples. fruit were stored for up to 16 w in dca with a 14 d of interruption with regular air (ra) at −0.5 °c, 95% rh. fruit was again stored in dca. the scald potential for each storage time in each season was assessed by storing fruit in ra and used as the control, in order to ascertain the efficacy of repeated dca treatments. superficial scald incidence, total soluble solids (tss), titratable acidity (ta), ground colour, fruit firmness and ethylene production were measured. alpha-farnesene and 6-methyl-5-hepten-2-one (mho) production were also measured using gas chromatography (gc–ms). principal component analysis (pca) was used to visualize metabolic changes and the relationship among them. results showed maximum superficial scald incidence of 2% and 99% in repeated dca and ra, respectively. fruit stored in dca repeatedly was characterized by a higher fruit firmness, ground colour and titratable acidity. ethylene, α-farnesene and mho production were significantly lower in repeated dca compared to only ra stored fruit. seasonal changes had no significant effect on metabolic parameters studied. the data distribution in the pca displayed two clusters that could easily be identified. these clusters allowed distinction between fruit stored in ra only and repeated dca. ethylene, α-farnesene and mho production had a strong and positive correlation with scald incidence. this study demonstrated that repeated dca treatments can effectively control superficial scald.
研究了重复动态控制气氛(dca)对granny smith苹果表面烫伤的控制作用。在-0.5°c，95%相对湿度下，将水果在dca中储存长达16 w，并中断14 d的常规空气(ra)。水果再次储存在dca中。为了确定dca重复治疗的有效性，通过在ra中贮藏水果并作为对照来评估每个季节贮藏时间的烫伤可能性。测定了表面烫伤发生率、总可溶性固形物(tss)、可滴定酸度(ta)、底色、果实硬度和乙烯生成量。用气相色谱法(gc-ms)测定了alpha-farnesene 和6-甲基-5-庚烯-2-酮(mho)的产量。采用主成分分析法(pca)观察代谢变化及其相互关系。结果表明，反复dca和ra患者表浅性烫伤的发生率分别为2%和99%。在dca中反复贮藏的果实具有硬度高、色泽浅、酸度可滴定等特点。在重复的dca中，乙烯、α-farnesene和mho的产量明显低于仅储存在ra中的水果。季节变化对所研究的代谢参数没有显著影响。pca中的数据分布显示了两个易于识别的簇。这些集群允许区分存储在ra中的水果和重复的dca。乙烯、α-farnesene和mho的产生与烫伤发生率有很强的正相关。本研究表明，反复dca调控可有效控制浅表烫伤。