Modulated Light Dependence of Growth, Flowering, and the Accumulation of Secondary Metabolites in Chilli

Abstract

Chili is widely used as a food additive and a flavouring and colouring agent and also has great importance in health preservation and therapy due to the abundant presence of many bioactive compounds, such as polyphenols, flavonoids, carotenoids, and capsaicinoids. Most of these secondary metabolites are strong antioxidants. In the present study, the effect of light intensity and spectral composition was studied on the growth, flowering, and yield of chilli together with the accumulation of secondary metabolites in the fruit. Two light intensities (300 and 500 μmol m–2 s–1) were applied in different spectral compositions. A broad white LED spectrum with and without FR application and with blue LED supplement was compared to blue and red LED lightings in different (80/20 and 95/5%) blue/red ratios. High light intensity increased the harvest index (fruit yield vs. biomass production) and reduced the flowering time of the plants. The amount of secondary metabolites in the fruit varied both by light intensity and spectral compositions; phenolic content and the radical scavenging activity were stimulated, whereas capsaicin accumulation was suppressed by blue light. The red colour of the fruit (provided by carotenoids) was inversely correlated with the absolute amount of blue, green, and far-red light. Based on the results, a schematic model was created, representing light-dependent metabolic changes in chilli. The results indicated that the accumulation of secondary metabolites could be modified by the adjustment of light intensity and spectral composition; however, different types of metabolites required different light environments.

Phytochemical profile of Capsicum spp. fruits related to ripeness level, shading and harvest season in the Southeast of Mexico

“…The increase in the total content of secondary metabolites in these chili peppers grown under conditions with a greater incidence of sunlight can also modify the profile of these metabolites, as has been observed in spectral composition studies (Darko et al, 2022;Jiménez-Viveros et al, 2023). Since the fruits of C. annuum var.…”

“…However, just like the amount of incident light influences growth (Jiménez-Leyva et al, 2022) and the content of secondary metabolites in Capsicum; the spectral composition also affects the concentration of these compounds. Blue light increases the content of phenolic acids and flavonoids and decreases the content of capsaicin (CAP) (Darko et al, 2022). Recently, De la Cruz-Ricardez et al (2023) observed that the total contents of phenolic compounds, flavonoids and carotenoids in the fruits of C. annuum var.…”

Modulation of Antioxidant Compounds in Fruits of Citrus reticulata Blanco Using Postharvest LED Irradiation

“…The qualitative analysis of the phenolic fruit profile provides detailed information on phenolic compounds, especially flavonoids, up-or down-regulated by light quality treatments. In the peel and pulp of RB fruits, some flavones, flavanols, anthocyanidins, and benzoic and cinnamic acids increased, suggesting that these specific molecules mainly contributed to phenolic accumulation under RB treatment [36], which likely has acted on the phenylpropanoid pathways involved in the biosynthesis of some flavonoids, i.e., sinensetin, and linarin, especially in the peel. The augment of such compounds is worthy of attention because sinensetin has been recognized to have potent antioxidant, anti-inflammatory, anticancer, and antimicrobial activity [37].…”

Dry mass input into fruits can be predicted by fine root morphology of pepper cultivars exposed to varied lighting spectra

“…None of our pepper cultivars loaded any bell fruits in the green light. The green light was also reported to be irrelevant from fruiting in chilli pepper (Darko et al, 2022) and sweet pepper (Maroga et al, 2019). It is a common sense that the green light has an extremely low absorptivity absorbed by photosynthetic pigments (Liu et al, 2021;Wei et al, 2020b).…”