Chemical Composition of Tomato Seed Flours, and Their Radical Scavenging, Anti-Inflammatory and Gut Microbiota Modulating Properties

Abstract

In the current study, the chemical composition and total phenolic content of tomato seed flours, along with potential health beneficial properties, including free radical scavenging capacities, anti-inflammatory capacities, and gut microbiota profile modulation, were examined using two different batches. Eight compounds were identified in the tomato seed flour, including malic acid, 2-hydroxyadipic acid, salicylic acid, naringin, N-acetyl-tryptophan, quercetin-di-O-hexoside, kaempferol-di-O-hexoside, and azelaic acid. The total phenolic contents of tomato seed flour were 1.97–2.00 mg gallic acid equivalents/g. Oxygen radical absorbing capacities (ORAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacities (DPPH), and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical scavenging capacities (ABTS) were 86.32–88.57, 3.57–3.81, and 3.39–3.58 µmoles Trolox equivalents/g, respectively, on a per flour dry weight basis. The mRNA expression of the pro-inflammatory markers, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), were dose-dependently suppressed by tomato seed flour extracts. The extracts altered five of the eight bacterial phyla and genera evaluated. The results may provide some scientific support for the use of tomato seed flour as value-added food ingredients.

Soluble Free, Soluble Conjugated, and Insoluble Bound Phenolics in Tomato Seeds and Their Radical Scavenging and Antiproliferative Activities

“…Azelaic acid was also found in the soluble free, soluble conjugated, and insoluble bound fractions with relative intensity of 130, 95, and 870, respectively (Table ). Azelaic acid is a dicarboxylic acid compound reported in tomato seeds in our previous study and also widely found in many different grains . Azelaic acid can be used to suppress in vivo antioxidant stress and treat acne vulgaris. , p -Coumaric acid was found in both soluble conjugated and insoluble bound fractions, with relative intensity of 390 and 630, respectively (Table ).…”

“…Naringenin is a flavanone found in many natural foods and may possess health-beneficial effects, suggesting the potential health-beneficial effects of tomato seeds. It is also an aglycone of naringenin 7-rhamnoglucoside detected in the 50% acetone extract of tomato seed flours . Salicylic acid was a common phenolic acid compound found in the 50% acetone extract of tomato seed flours in our previous study and has been used as anti-inflammatory components in aspirin .…”

“…It is also an aglycone of naringenin 7-rhamnoglucoside detected in the 50% acetone extract of tomato seed flours . Salicylic acid was a common phenolic acid compound found in the 50% acetone extract of tomato seed flours in our previous study and has been used as anti-inflammatory components in aspirin . In the soluble conjugated fraction of tomato seeds, p -coumaric acid, naringenin-7- O -glucoside, azelaic acid, and hydroxytyrosol are the four major peaks, with relative intensity of 390, 97, 95, and 91, respectively (Table ).…”

“…A UHPLC–HRMS system comprising a Vanquish UHPLC system with an Orbitrap Fusion ID-X Tribrid mass spectrometer was used to analyze the chemical compositions of the soluble free, soluble conjugated, and insoluble bound phenolics in tomato seeds . The separation was carried out on an Agilent Eclipse Plus-C 18 UHPLC column (150 mm × 2.1 mm i.d., 1.8 μm) (Aglient, Santa Clara, CA, USA) with an UltraShield pre-column filter (Analytical Scientific Instruments, Richmond, CA, USA) at a flow rate of 0.3 mL/min.…”

“…Recent studies showed that tomato seeds are rich in phenolic compounds and possessed excellent health beneficial effects including antioxidant, anti-inflammatory, and gut microbiota modulation activities. , Our recent study found that 50% acetone extracts of tomato seed flours were able to effectively scavenge ABTS •+ , DPPH • , and peroxyl radicals, suppress mRNA expression of the pro-inflammatory markers, and modulate gut microbiota in vitro . Eight compounds including three flavonoids, one phenolic acid, one amino acid derivative, and three dicarboxylic acids were identified in the extract and considered as the major components contributing to the observed bioactivities . Ferreres and others also reported the phenolic composition of 50% methanol extracts of tomato seeds, particularly quercetin, kaempferol, and isorhamnetin and their derivatives .…”