Comparison of autoclaving and γ-radiation impact on four spices aroma profiles and microbial load using HS-SPME GC-MS and chemometric tools.

Herbal spices are widely consumed as food additives owing to their distinct aroma and taste as well as a myriad of economic and health value. The aroma profile of four major spices including bay leaf, black pepper, capsicum, and fennel was tested using HS-SPME/GC-MS and in response to the most widely used spices´ processing methods including autoclaving and γ-radiation at low and high doses. Additionally, the impact of processing on microbial contamination of spices was tested using total aerobic count. GC-MS analysis led to the identification of 22 volatiles in bay leaf, 34 in black pepper, 23 in capsicum, and 24 in fennel. All the identified volatiles belonged to oxides/phenols/ethers, esters, ketones, alcohols, sesquiterpene and monoterpene hydrocarbons. Oxides/phenol/ethers were detected at high levels in all tested spices at ca. 44, 28.2, 48.8, 61.1%, in bay leaves, black pepper, capsicum, and fennel, respectively of the total blend and signifying their typical use as spices. Total oxides/phenol/ethers showed an increase in bay leaf upon exposure to γ-radiation from 44 to 47.5%, while monoterpene hydrocarbons were enriched in black pepper upon autoclaving from 11.4 in control to reach 65.9 and 82.6% for high dose and low dose of autoclaving, respectively. Cineole was detected in bay leaf at 17.9% and upon exposure to autoclaving at high dose and γ-radiation (both doses) its level increased by 29-31%. Both autoclaving and γ-radiation distinctly affected aroma profiles in examined spices. Further, volatile variations in response to processing were assessed using multivariate data analysis (MVA) revealing distinct separation between autoclaved and γ-radiated samples compared to control. Both autoclaving at 115 °C for 15 min and radiation at 10 kGy eliminated detected bioburden in all tested spices i.e., reduced the microbial counts below the detection limit (< 10 cfu/g).

How do cultivar origin and stepwise industrial processing impact Sesamum indicum seeds' metabolome and its paste and in relation to their antioxidant effects? A case study from the sesame industry.

Sesame is a valuable crop recognized for its rich composition and myriad of health benefits. The current study attempts to characterize sesame seeds' metabolome in relation to geographical origins i.e., Egypt, Sudan, Nigeria, in addition to samples from paste production lines along its different steps. UPLC-PDA-ESI-qTOF-MS was employed for untargeted profiling and in correlation to antioxidant capacity using DPPH, FRAP and ß-carotene-lineolate assays. 139 Peaks were identified, including novel phospholipids and catechol lignan in sesame. Furthermore, discriminatory markers belonging to coumarins, lignans, phenolic and organic acids were revealed among raw accessions, whereas roasted and unroasted seeds were distinguished by sugar, peptide/amino acid, and organic acid contents. Negative processing impact was observed in the loss of lignans during dehulling and decreased antioxidant capacity in sesame paste. However, malic acid in roasted seeds and verbascoside in Nigerian sesame could account for their improved antioxidant effects as revealed using chemometrics.

Unveiling metabolome heterogeneity and new chemicals in 7 tomato varieties via multiplex approach of UHPLC-MS/MS, GC-MS, and UV-Vis in relation to antioxidant effects as analyzed using molecular networking and chemometrics.

Tomatoes show diverse phytochemical attributes that contribute to their nutritive and health values. This study comprehensively dissects primary and secondary metabolite profiles of seven tomato varieties. UHPLC-qTOF-MS assisted molecular networking was used to monitor 206 metabolites, 30 of which were first-time to be reported. Flavonoids, as valuable antioxidants, were enriched in light-colored tomatoes (golden sweet, sun gold, and yellow plum) versus high tomatoside A, an antihyperglycemic saponin, in cherry bomb and red plum varieties. UV-Vis analysis revealed similar results with a strong absorbance corresponding to rich phenolic content in light varieties. GC-MS unveiled monosaccharides as the main contributors to samples' segregation, found abundant in San Marzano tomato accounting for its sweet flavor. Fruits also demonstrated potential antioxidant activities in correlation to their flavonoids and phospholipids. This work provides a complete map of tomatoes' metabolome heterogeneity for future breeding programs and a comparative approach utilizing different metabolomic platforms for tomato analysis.