Characterization of aroma-active compounds in sesame hulls at different roasting temperatures by SAFE and GC-O-MS

The study characterized the aroma-active compounds produced by sesame hulls at three roasting temperatures and analyzed the similarities and differences in the aroma profile of sesame hulls with whole seeds and kernels after roasting. Roasting hulls produced mainly furans, aldehydes, and ketones volatiles. 140 Compounds were identified as aroma-active compounds, including 36 key aroma compounds (odor activity value, OAV ≥ 1). Among them, furanone (caramel-like, OAV = 80), 3-methylbutanal (fruity, OAV = 124), and 2-methoxy-4-vinylphenol (burnt, smoky, OAV = 160) gave hulls (180 °C) sweet, burnt, and smoky aroma. Due to the contribution of vanillin (fatty, sweet milk, OAV = 45), 2-hydroxy-3-butanone (caramel-like, roast, OAV = 46), and 2-methoxy-4-vinylphenol (OAV = 78), hulls (200 °C) shown strong sweet and roast note. These results identified compounds that contributed significantly to the aroma of sesame hulls and elucidated the contribution of sesame hulls to the flavor of roasted whole seeds and sesame oil.

Qualitative and quantitative assessment of key aroma compounds, advanced glycation end products and heterocyclic amines in different varieties of commercially roasted meat products

Studies on the interactions and links between aroma and hazardous compounds were inadequately investigated. A complete analysis was conducted on the key aroma compounds, typical hazardous compounds and their precursors in 25 samples of roasted meats. Forty-nine aroma compounds were identified as essential odorants with odor-activity values exceeds 1. Nε-carboxymethyl lysine (CML, 11.78-49.32 μg/g) and Nε-carboxyethyl lysine (CEL, 8.48-171.00 μg/g) were identified as representative advanced glycation end products (AGEs) of meats with high concentrations. Harman and Norharman were typical heterocyclic aromatic amines. Meanwhile, correlation analysis indicated that aldehyde and alcohols showed a negative correlation with AGEs (p < 0.01), while pyrazines might affect the formation of Harman and Norharman. The furaldehyde, 1-hexanol, 2, 4-Decadienal, AGEs, and creatine were regarded as potential biomarkers that distinguished different roasted meat products. Therefore, the study could provide new insights for synergistic regulation of aroma and hazardous compounds in roasted meat products.

Effect of thermal treatment on the extraction efficiency, physicochemical quality of Jatropha curcas oil, and biological quality of its proteins

Jatropha curcas seeds are an important source of oil (5-60%), used to obtain biodiesel. The generated residual paste has a high concentration of proteins (50-55%); however, the seeds contain non-nutritional factors that limit their use. The objective of this work was to analyze the effect on the physicochemical properties of the oil obtained from J. curcas seeds subjected to different thermal treatments and to evaluate the biological quality of the proteins contained in the residual cake. The best extraction of oil (95%) was obtained after 10 h from roasted or boiled seeds. In the oil from roasted samples, the acid index increased significantly (p ≤ 0.05) with respect to the untreated sample, whereas the iodine index increased significantly (p ≤ 0.05) in the oil extracted from the boiled samples. With respect to the proximal chemical composition of the flour, roasting and boiling treatments allowed for greater oil extraction (97 and 92%), achieving, in turn, a higher content of proteins (59.56 and 58.5 g/100 g) and fiber (6.67 and 6.67 g/100 g), and lower activity of trypsin inhibitors (45 and 38%) and phytates (63 and 72%), respectively. According to the in vivo biological quality test, conducted on Wistar rats, the thermal treatments applied to the seeds improved digestibility (> 70%) and the protein efficiency index (PER). The thermal treatment allowed extracting more efficiently the oil and improved the quality of the proteins present in the residual paste.

Effects of thermal preparation and in vitro digestion on lignan profiles and antioxidant activity in defatted-sesame meal

Defatted-sesame meal (DSM), a byproduct of sesame oil, has attracted considerable interest in the food industry because of its strong antioxidant activity. The aim of this study was to measure the content and distribution of lignans in DSM and evaluate their antioxidant activity after thermal processing and in vitro digestion. The results showed that the sesame lignans (SL) content and antioxidant activity were significantly influenced by the temperature and time during thermal preparation, and the maximum antioxidant potency composite index (ACI) was obtained after roasting the samples at 240 °C for 20 min. As sesame seed was processed with longer time and higher temperature, more pinoresinol diglucoside (PD) and sesamol were measured in DSM. According to the correlation matrix under thermal preparation, a significant contribution to the antioxidant potency of DSM was discovered. After in vitro digestion, the release amount of lignans increased by 19.6%, and the values of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ACI gradually declined after digestion, with a 40% decrease in both the DPPH radical scavenging activity and the ACI from oral to intestinal phase. These results could be used to help improve the bioavailability of SL and obtaining high quality sesame byproducts.

Nutrient database improvement project: the influence of U.S.D.A. Quality and Yield Grade on the separable components and proximate composition of raw and cooked retail cuts from the beef rib and plate

Beef nutrition is important to the worldwide beef industry. The objective of this study was to analyze proximate composition of eight beef rib and plate cuts to update the USDA National Nutrient Database for Standard Reference (SR). Furthermore, this study aimed to determine the influence of USDA Quality Grade on the separable components and proximate composition of the examined retail cuts. Carcasses (n=72) representing a composite of Yield Grade, Quality Grade, gender and genetic type were identified from six regions across the U.S. Beef plates and ribs (IMPS #109 and 121C and D) were collected from the selected carcasses and shipped to three university meat laboratories for storage, retail fabrication, cooking, and dissection and analysis of proximate composition. These data provide updated information regarding the nutrient content of beef and emphasize the influence of common classification systems (Yield Grade and Quality Grade) on the separable components, cooking yield, and proximate composition of retail beef cuts.