棚龄对大棚种植黄瓜品质影响的傅里叶变换红外光谱研究

蔬菜大棚种植对蔬菜供应发挥着重要的作用，蔬菜大棚棚龄会影响蔬菜的产量和质量。以不同棚龄（1年、10年和18年）的黄瓜为对象，利用漫反射傅里叶变换中红外光谱，通过解析黄瓜的光谱特征峰，探究棚龄对黄瓜品质的影响。研究表明，黄瓜的多糖和蛋白质组分在3个棚龄呈现先增加后降低的趋势，10年棚龄种植的黄瓜多糖和蛋白质组分显著高于1年和18年的黄瓜多糖和蛋白质组分。高的棚龄（即10年和18年）显著增加了黄瓜的木质素组分。木质素组分主要分布于黄瓜皮中，增加木质素组分会降低黄瓜的食用口感。另外，黄瓜中各有机组分的比值能综合反映不同棚龄下黄瓜的品质。18年棚龄的黄瓜多糖与蛋白质组分的比值以及多糖与木质素组分的比值低于1年和10年棚龄的黄瓜各有机组分的比值，表明1年和10年棚龄的黄瓜中碳水化合物和营养物质的比值更加均衡。通过分析黄瓜各有机组分以及黄瓜各有机组分比值随着黄瓜棚龄的变化，知悉黄瓜棚龄在10年以内时，对黄瓜品质提升具有促进作用，但更长的棚龄会抑制黄瓜品质。因此，综合考虑黄瓜的品质，建议黄瓜棚龄不宜太长。另外，通过分析棚龄对黄瓜叶片有机组分的影响，发现黄瓜叶片各组分与黄瓜各组分的变化趋势相似。线性相关分析指出黄瓜蛋白质和木质素组分分别与黄瓜叶片蛋白质和木质素组分显著正相关，表明黄瓜叶片在一定程度上能反映黄瓜的营养成分和黄瓜口感。利用红外光谱解析不同棚龄下表征黄瓜品质的有机组分，为蔬菜大棚管理以及提高蔬菜品质提供了科学依据。

Study on the Effects of Planting Years of Vegetable Greenhouse on the Cucumber Qualties Using Mid-IR Spectroscopoy

Greenhouse vegetable cultivation plays a crucial role in global vegetable supply. The planting year of vegetable greenhouses greatly affects vegetable yield and quality, whereas the study on vegetable quality using infrared spectroscopy is still unclear. Therefore, the mid-IR spectroscopy was used to detect how planting year of vegetable greenhouses (i.e., 1 year, 10 years, and 18 years) influenced cucumber quality by analyzing the specific peaks of cucumber fruits and leaves. In our study, the polysaccharides and protein components in cucumber fruits initially increased (the highest in 10 years) and subsequently decreased during the progression of the planting year. Raising planting years (i.e., 10 years and 18 years) increased lignin components of cucumber fruits (mainly in cucumber peel), which reduced the cucumber’s taste. In addition, the ratio of organic components in cucumber can reflect cucumber quality under different greenhouse planting years. Polysaccharide/protein components and polysaccharide/lignin components in 18 years were significantly lower than those in 1 year and 10 years, implying that cucumbers of 1 year and 10 years had well-balanced carbohydrates and nutrients. Our finding suggests that short-term planting years (e.g., within 10 years) can improve cucumber quality, but long-term planting years inhibit cucumber quality. Therefore, comprehensively considering cucumber quality, we suggested that the planting year of the cucumber greenhouse should not be too long. Additionally, the organic components of cucumber leaves showed a similar trend to organic cucumber components across greenhouse planting years. Linear regression analysis demonstrated that cucumber fruits’ protein and lignin components were positively associated with the protein and lignin components of cucumber leaves, which indicated that cucumber leaves might represent the nutrient and taste cucumber fruit. Overall, this study revealed the changes in organic cucumber components by mid-IR spectroscopy paralleled changed cucumber quality, providing scientific evidence for vegetable greenhouses management and improving vegetable quality.