Min Qianxixi, Marcelis Leo F M, Nicole Celine C S, Woltering Ernst J
Horticulture and Product Physiology Group, Wageningen University and Research, Wageningen, Netherlands.
Signify Research Laboratories, Eindhoven, Netherlands.
Front Plant Sci. 2021 Jan 28;12:615355. doi: 10.3389/fpls.2021.615355. eCollection 2021.
The effect of light intensity applied shortly before harvest on the nutritional quality, postharvest performance, and shelf life of loose-leaf lettuce ( L. cv. Expertise RZ Salanova) was investigated. Lettuce was grown either in a greenhouse with supplemental high-pressure sodium light (Experiment 1, EXP 1) or in a climate room under white LED light (Experiment 2, EXP 2). In both experiments full grown plants were transferred to a climate room for the End of Production (EoP) light treatments during the last week of cultivation. During EoP lighting plants were exposed to different intensities (0, 110, and 270 μmol m s in EXP 1; 50, 210, and 470 μmol m s in EXP 2) from white-red LEDs for 6 (EXP 2) or 7 days (EXP 1). Mature leaves were then harvested and stored in darkness at 10°C to study the postharvest performance. Changes in dry matter content, total ascorbic acid, and carbohydrates (including glucose, fructose sucrose, and starch) levels were determined during EoP lighting and during the subsequent shelf life as indicators of lettuce nutritional quality. Quality aspects (appearance, texture, and odor) were accessed during the shelf life as indicators of postharvest performance. In both experiments, high light intensities applied in EoP lighting increased dry matter percentage and contents of ascorbic acid (AsA) and carbohydrates at harvest and these increased levels were maintained during the shelf life. Increased light intensity in EoP treatment also extended the shelf life. The levels of AsA and carbohydrates at harvest correlated positively with the subsequent shelf life, indicating that the prolonged shelf life relies on the improved energy and antioxidant status of the crop at harvest.
研究了收获前短时间施加的光照强度对散叶生菜（L. cv. Expertise RZ Salanova）营养品质、采后性能和货架期的影响。生菜分别种植在配备补充高压钠灯的温室中（实验1，EXP 1）或白色LED灯下的气候室中（实验2，EXP 2）。在两个实验中，在栽培的最后一周，将完全成熟的植株转移到气候室进行生产末期（EoP）光照处理。在EoP光照期间，植株接受来自红白光LED的不同强度光照（实验1中为0、110和270 μmol m⁻² s⁻¹；实验2中为50、210和470 μmol m⁻² s⁻¹），持续6天（实验2）或7天（实验1）。然后收获成熟叶片并在10°C黑暗条件下储存，以研究采后性能。在EoP光照期间和随后的货架期内，测定干物质含量、总抗坏血酸和碳水化合物（包括葡萄糖、果糖、蔗糖和淀粉）水平的变化，作为生菜营养品质的指标。在货架期内评估品质方面（外观、质地和气味），作为采后性能的指标。在两个实验中，EoP光照中施加的高光强增加了收获时的干物质百分比以及抗坏血酸（AsA）和碳水化合物含量，并且这些增加的水平在货架期内得以维持。EoP处理中光照强度的增加也延长了货架期。收获时AsA和碳水化合物的水平与随后的货架期呈正相关，表明延长的货架期依赖于收获时作物能量和抗氧化状态的改善。
