Gude Kelly, Talavera Martin, Sasse Audra M, Rivard Cary L, Pliakoni Eleni
Department of Horticulture & Natural Resources, Kansas State University, 22201 West Innovation Drive, Olathe, KS 66061, USA.
Department of Food, Nutrition, Dietetics and Health, Kansas State University, 22201 West Innovation Drive, Olathe, KS 66061, USA.
Foods. 2021 Nov 2;10(11):2660. doi: 10.3390/foods10112660.
Leafy green production in high tunnels (HTs) results in increased yields, improved visual quality, and extended production with polyethylene (poly) film and/or shade cloth coverings. However, altering visible and ultra-violet light with HT coverings may reduce phytochemicals, thus influencing plant pigmentation and taste. The objective of this study was to examine various HT coverings on the sensory perceptions, soil temperature, color, and anthocyanin accumulation of red leaf lettuce. The coverings included standard poly, standard poly with removal two weeks prior to harvest (movable), diffuse poly, clear poly, UV-A/B blocking poly (block), standard poly with 55% shade cloth, and the open field. A highly trained descriptive panel evaluated the samples using a scale from 0 (none) to 15 (extremely high) and determined a list of 20 sensory attributes. The color intensity attribute had the most differentiation between coverings, and the open field was higher (i.e., darker) than the others at 7.5 ( < 0.0001), followed by clear and movable coverings at 6.8, and the shade covering scored a 2. Strong relationships existed between both colorimetric (hue°) and anthocyanin analysis to panelist-based scores (R = 0.847 and 0.640, respectively). The initial crispness was similar for movable, standard, diffuse, and block coverings at 5.3 on average, which was higher than the open field at 4 ( < 0.01). The open field lettuce grew under cooler soil temperatures, which may have slowed down maturation and resulted in softer tissue. Based on this study, HT growers can implement specific coverings to cater to markets that value visual quality.
在高拱棚（HTs）中种植绿叶蔬菜，使用聚乙烯（poly）薄膜和/或遮阳网覆盖可提高产量、改善外观品质并延长生产期。然而，高拱棚覆盖物改变可见光和紫外线可能会减少植物化学物质，从而影响植物色素沉着和口感。本研究的目的是研究不同的高拱棚覆盖物对红叶生菜感官认知、土壤温度、颜色和花青素积累的影响。覆盖物包括标准聚乙烯、收获前两周移除的标准聚乙烯（可移动）、漫反射聚乙烯、透明聚乙烯、紫外线A/B阻挡聚乙烯（阻挡）、带55%遮阳网的标准聚乙烯以及露地。一个训练有素的描述性评估小组使用从0（无）到15（极高）的量表对样品进行评估，并确定了20个感官属性列表。颜色强度属性在不同覆盖物之间差异最大，露地的颜色强度最高（即颜色最深），为7.5（<0.0001），其次是透明和可移动覆盖物，为6.8，遮阳覆盖物得分为2。比色法（色调°）和花青素分析与基于评估小组成员的评分之间都存在很强的相关性（R分别为0.847和0.640）。可移动、标准、漫反射和阻挡覆盖物的初始脆度平均为5.3，相似，高于露地的4（<0.01）。露地生菜在较低的土壤温度下生长，这可能减缓了成熟速度并导致组织更软。基于本研究，高拱棚种植者可以采用特定的覆盖物来迎合重视外观品质的市场。
