ACS food science & technology最新文献

Six-carbon (C₆) carbonyls formed from lipid oxidation (e.g., hexanal, (E)-2-hexenal) are routinely used as quality markers in the food industry. Typically, these carbonyls are measured by gas chromatography–mass spectrometry (GC-MS) or related approaches. Recent work demonstrates that parallel extraction of headspace volatiles using sorbent sheets (HS-SPMESH) followed by direct analysis in real-time mass spectrometry (DART-MS) can be used as a rapid alternative to GC-MS. However, SPMESH-DART-MS measurement of C₆ carbonyls is complicated by their low extractability onto polydimethylsiloxane-based SPMESH sheets and poor DART-MS ionization behavior. This work reports on the development and validation of a rapid HS-SPMESH-DART-MS approach to measurement of C₆ carbonyls following their in situ derivatization with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine in multiple food matrices including grape juice, soy milk, conventional milk, and mayonnaise. Including derivatization and extraction time, the method can analyze 24 samples in ∼60 min with good recovery, linearity, and reproducibility, and with detection limits of 0.25 and 3.1 μg/L, for hexanal and (E)-2-hexenal, respectively.

Food-derived peptides and polyphenols have demonstrated antioxidant activities against reactive oxygen species and free radicals. However, little is known about their combined antioxidant capacity when they interact within a mixture. This study investigated the antioxidant capacity of a mixture of flavonoids (quercetin or rutin) and pea protein-derived pentapeptide (VNRFR) in vitro and in vivo using the Caenorhabditis elegans model. Dynamic light scattering, spectroscopic, and molecular docking analysis revealed the formation of peptide–polyphenol complexes, with the polyphenolic aromatic ring and peptide phenylalanine residue interacting noncovalently by π-stacking. The interaction resulted in antagonistic radical scavenging activity in vitro and antioxidative effects in vivo based on the nematode mean lifespan and survival rate, and intracellular reactive oxygen species levels. Notably, the antagonism was more pronounced for rutin due to the additional H-bonding that its rhamnosyl-glucoside moiety formed with the peptide. The findings provide valuable insights into food matrix interactions that affect the antioxidant capacity of nutraceutical mixtures in formulated products.

Protein removal with aspergillopepsin in combination with short-time heating has recently emerged as an opportunity for winemakers to prevent protein haze in wine. In this study, we first treated a protein-rich must and wine with two different aspergillopepsin preparations along an identical control treatment without enzyme addition on a pilot plant scale. While treating wines was rather ineffective, treating musts was effective in reducing protein concentrations by up to 86%, leading to haze-stable wines according to the common heat test. Varying thermal loads in further experiments, a rather mild heat treatment of 65 °C for 30 s compared to those in earlier studies was found sufficient for enzymatic protein degradation. Treating must from a fungus-resistant variety (cv. Fidelio) was as successful as treating must from a blend of conventional varieties (cv. Gewürztraminer/Müller-Thurgau). Triangle sensory tests found no clear evidence of an effect on the quality by heat treatments with and without enzyme dosage.

The thermal resistance of avirulent Salmonella Typhimurium in yolk, albumen, and liquid whole egg (LWE) was evaluated from 52 to 60 °C. A log–linear and a Weibullian model were used to calculate D- and z-values. Experiments assessed and overseen the come-up time (CUT). Results showed a longer inactivation time for Salmonella in yolk (D_58 °C = 2.32 min) compared to albumen (D_58 °C = 0.36 min); D-values for LWE were D_58 °C= 1.26–1.28 min. The protective effect of the yolk fat in Salmonella was observed under the microscope. The effect of CUT was only significantly different (α = 0.05) at 60 °C. The Weibull model best fitted the survival data (R², root square mean error, Akaike Information Criterion). The 5D pasteurization standard for this avirulent Salmonella strain at 60 °C was 3.3 ± 0.3 min (log–linear) and 3.6 ± 0.2 min (Weibull). This Salmonella strain has an average heat resistance; it can be used for process validation without safety risks.