Lipidomics-Based Comparison of Molecular Compositions of Green, Yellow, and Red Bell Peppers

Abstract

Identifying and annotating the molecular composition of individual foods will improve scientific understanding of how foods impact human health and how much variation exists in the molecular composition of foods of the same species. The complexity of this task includes distinct varieties and variations in natural occurring pigments of foods. Lipidomics, a sub-field of metabolomics, has emerged as an effective tool to help decipher the molecular composition of foods. For this proof-of-principle research, we determined the lipidomic profiles of green, yellow and red bell peppers (Capsicum annuum) using liquid chromatography mass spectrometry and a novel tool for automated annotation of compounds following database searches. Among 23 samples analyzed from 6 peppers (2 green, 1 yellow, and 3 red), over 8000 lipid compounds were detected with 315 compounds (106 annotated) found in all three colors. Assessments of relationships between these compounds and pepper color, using linear mixed effects regression and false discovery rate (<0.05) statistical adjustment, revealed 11 compounds differing by color. The compound most strongly associated with color was the carotenoid, β-cryptoxanthin (p-value = 7.4 × 10−5; FDR adjusted p-value = 0.0080). These results support lipidomics as a viable analytical technique to identify molecular compounds that can be used for unique characterization of foods.

Bell Peppers (Capsicum annum L.) Losses and Wastes: Source for Food and Pharmaceutical Applications

“…However, after processing bell pepper products, waste remains (seeds, peel, stem, and leaves), representing desirable raw material to obtain phytochemical compounds [ 20 ]. They contain diverse bioactive compounds with interesting biological activities (in vivo and in vitro) and applications [ 31 ]. Bioactive compounds are defined as “inherent non-nutrient constituents of food plants with anticipated health-promoting/beneficial and/or toxic effects when ingested” [ 32 ].…”

“…6-rhamnose 8-glucose (170 µg/g), and Apig. 6-arbinose 8-galactose (151 µg/g) [ 29 , 30 , 31 , 34 , 35 ]; while in red bell pepper, hesperidin (1513 µg/g), catechin (793 µg/g), luteolin 7-glucose (413 µg/g), Apig. 6-rhamnose 8-glucose (314 µg/g), rutin (290 µg/g), quercetin (241 µg/g), and Apig.…”

“…On the other hand, in the yellow bell pepper, catechin (745 µg/g), hesperidin (213 µg/g), naringin (190 µg/g), quercetin (102 µg/g), luteolin (95 µg/g), luteolin 7-glucose (92 µg/g), and Apig. 6-arbinose 8-glucose (77 µg/g) [ 29 , 30 , 31 , 34 , 35 ] were reported. Moreover, the presence of quercetin (92 µg/g) and luteolin (56 µg/g) has been reported in orange bell pepper fruit [ 30 ].…”

“…Other bioactive compounds such as colneleic acid, capsoside A, gingerglycolipid A, and blumenol C glucoside have been qualitatively identified in red and yellow bell pepper fruits [ 36 ]. Stuliff et al [ 31 ] reported 57 glycerolipids and glycerophospholipids, two sphingomyelin compounds and ceramides in green, yellow, and red bell peppers. These compounds could exert interesting biological activities.…”

Metabolomic Analysis Identifies Differences Between Wild and Domesticated Chili Pepper Fruits During Development (Capsicum annuum L.)

“…In Capsicum annuum L. cv. Bell pepper, Sutliff et al (2021) reported the presence of 57 glycerophospholipids and glycerolipids compounds in the mature fruits. The selection of fruit color traits could be associated with the modification of nutritional characteristics in bell pepper ( Sutliff et al, 2021 ).…”