ACS food science & technology最新文献

The synthesis of long-chain n-3 polyunsaturated fatty acid (n-3 PUFA) triacylglycerols (TAGs) via lipase-catalyzed esterification is crucial for optimal human nutrition. However, existing lipases lack selectivity for long-chain n-3 PUFAs, hindering the efficient synthesis of highly polyunsaturated TAGs. By two-dimensional NMR and quantum chemical calculations, polyunsaturated DHA was found to have a unique curved conformation. We rationally designed the lipase MAS1 from marine Streptomyces sp. Strain W007 was based on the bent conformation of DHA, using virtual saturation mutagenesis and binding free energy calculations. Consequently, D150V with more hydrogen bonds and a lower binding free energy to DHA (−28.3820 kcal/mol) was obtained. The esterification selectivity of D150V to DHA was 2.18-fold that of the wild type, whereas its selectivity to behenic acid exhibited minimal improvement. Collectively, our findings present a significant advancement in lipase design for selective long-chain n-3 PUFA esterification, thereby opening avenues for lipase modification and industrial applications.

Biopolymers derived from natural resources have gained much interest in the past few decades to replace conventional nonbiodegradable petroleum-based packaging. Essential oils and plant extracts are frequently utilized for their antimicrobial and antioxidant properties in the development of edible films and coatings serving as bioactive compounds. The current study investigated the impact of various concentrations of lemongrass essential oil (LEO) on the physical and chemical characteristics as well as the antioxidant capabilities of films made from sodium caseinate and pectin. The addition of LEO led to a decrease in mechanical parameters of film samples like elongation at break (EAB) decreased from 19.73 ± 0.81 to 4.06 ± 0.20 and tensile strength (TS) decreased from 11.16 ± 0.81 to 2.43 ± 0.08 but a rise in opacity (4.39 ± 0.14 to 5.60 ± 0.13), thickness (0.044 ± 0.005 to 0.078 ± 0.005), and water vapor permeability (WVP) (0.391 ± 0.013 to 0.760 ± 0.035) was observed. The gloss value of the film samples increased from 11.9 ± 0.1 to 13.1 ± 0.1, and haziness increased from 45.85 ± 1.05 to 71.69 ± 0.25 as the concentration of LEO increased, reducing their transparency (89.22 ± 0.27–88.24 ± 0.19). Scanning electron microscopy (SEM) revealed additional microstructural alterations in the films as a result of the addition of LEO. Furthermore, antimicrobial activity was detected in the PSC4 film sample against E. coli. The oil-loaded films showed significantly higher antioxidant activity of 40.41% compared to the control film sample, having 16.57% antioxidant activity. Contact angle measurements demonstrated that the film samples became more hydrophobic with the addition of LEO (55.52° in the maximum LEO concentrated film). This study introduces a promising method for creating active food packaging materials for packaging applications.

Kombucha is a naturally fermented beverage with a rich history of development and popularity among consumers. The microbial ecology and complex microbial communities during the fermentation process are key factors that drive fermentation and shape the quality characteristics of kombucha. Kombucha features a symbiotic culture of bacteria and yeast that exists in two distinct phases within the drink: the liquid portion and the biofilm, which floats on the surface. Most investigations focused on describing the microbial community, biochemical properties, and association networks of the beverage independently. Recently, a mechanistic understanding of assembly of microbiomes in kombucha has emerged. This review aims to explore the evolutionary patterns of the complex microbiota in kombucha fermentation, the central metabolic pathways, the influence of environmental factors on community structure, and its regulation effects on the final flavor of kombucha. Furthermore, this review summarizes the impact of microbiota on the physicochemical properties (e.g., pH, ethanol, oxygen and sugar levels) and biochemical parameters (e.g., organic acids, polyphenolic compounds, and volatiles) of kombucha in a systematic manner. The potential health benefits and potential risks are evaluated associated with consuming kombucha or its bioactive compounds. On this basis, this review discussed the future development potential of kombucha and the limitations of related studies, aiming to provide valuable insights into the prospective scientific research and industrialization of kombucha.

Mexican viticulture has achieved a notable global presence. This review aims to explore the main wine regions in Mexico and examine how geography, climate, and soil affect the quality of grapes and wine. A comprehensive research review was conducted using Google Scholar, Web of Science, and Scopus as search engines. Mexico has three wine regions with temperatures ranging from 8 to 30 °C and an average solar radiation of 1400 h per year. Their main soil types are acid, alluvial, alkaline, clay, sandy, and calcareous. Mexican grapes have high acidity and moderate sugar levels, yielding wines with complex profiles. Despite its favorable viticultural conditions, Mexico needs to increase studies focused on terroir characteristics and their impact on grape and wine quality. In the face of global climate change, it is crucial to implement modern technologies in viticulture that allow optimal agricultural practices and increase the production of high-quality grapes.

Our study evaluates the long-term preservation of extra virgin olive oil (EVOO) (using the Koroneiki monovariety Olea europaea var. Microcarpa alba, from the Aitoloakarnania region in Western Greece) as a function of storage temperature, duration, and ±gaseous N₂ purge under dark conditions by introducing the following innovative tests (applicable to all plant oils): (i) a peroxide value (PV) test that is specific for EVOO′s lipid hydroperoxides (designated PV_LOOH), the early-stage peroxidation product of polyunsaturated fatty acids (PUFAs), in contrast to the established nonspecific, unreliable, and less-sensitive iodometric test; and (ii) a test for EVOO′s free malondialdehyde (MDA), the late-stage peroxidation aldehydic product of PUFA, for measuring the Threshold of Toxicological Concern (TTC) for MDA dietary exposure levels (designated TTC_MDA-EL), a TTC concept that allows establishment of a level of exposure above which a toxicological concern may occur. It was found that the particular EVOO variety shows the best long-term preservation conditions with minimal change in PV_LOOH levels when stored at −20 °C for up to 1.5 years, regardless of ±N₂ purge; storage at 5 °C represents the second optimum condition, where PV_LOOH levels increase by 40% at +N₂ purge up to 1.5 years of storage. It was also found that TTC_MDA-EL levels follow a similar trend to PV_LOOH across the tested long-term preservation parameters. The study also introduces a minimum TTC dietary exposure level for MDA (TTC_MDA-ELmin), which reflects the most optimum extraction procedures and storage conditions for EVOO, relevant for all commercial plant oils and derived food products.

The microbial contamination and postharvest metabolism often result in the quality deterioration of fresh produce. To reduce the microbial load without compromising quality parameters of fresh produce, a combination of indirect cold plasma with modified atmosphere packaging was developed for preservation of cherry tomato, cucumber, and lettuce in this study. The impact on microbial decontamination and retardance of quality deterioration was investigated based on the evaluation of microbial proliferation and quality parameters. The combined treatment not only effectively reduced microbial load and rendered microbial proliferation at lower levels but also reduced the respiration rate by 29.1% compared with the control group. In addition, the combined treatment contributed to delaying the enzymatic browning process and scavenging excessive reactive oxygen species. The combined treatment extended the shelf life of fresh produce by an additional 2 days in this study. In brief, the combined treatment can be used as an alternative approach for microbial decontamination of fresh produce without adversely affecting quality attributes of fresh produce, assisting in extension of shelf life.

Mandarins, with their closely related taste characteristics and ability to change through phenomic and genomic technologies, offer an opportunity for detailed metabolic profiles. The organic acid profile, synephrine, total phenolic and flavonoid content, and carotenoid and volatile profile of four Satsuma mandarin varieties, Saigon, Kawano wase, Okitsu, and Kuno, were determined. The most prevalent organic acid in all four varieties was found to be citric acid, with Saigon having the highest value (11.17 g L^–1). The highest content of synephrine (104.41 mg L^–1) was found in Saigon juice. The levels of individual carotenoids detected in the mandarin peel have the highest values in Saigon, while the pulp of the Kuno variety is the richest in carotenoids. A total of 43 volatile compounds were determined. The most prevalent compounds in all four varieties were ocimene (1.084–262.29 μg kg^–1), β-myrcene (14.56–49.12 μg kg^–1), hexanal (3.70–31.04 μg kg^–1), and α-pinene (0.39–3.48 μg kg^–1).

In this study, we used desorption electrospray ionization–mass spectrometry imaging (DESI-MSI) to delineate the distribution of deoxynivalenol (DON), which is a common mycotoxin produced by Fusarium, in wheat grains. Initially, we identified grains with high levels of DON contamination by splitting them into two parts and quantifying DON in one part using liquid chromatography–mass spectrometry. Subsequently, we visualized the distribution of DON in the other part of the grains using the optimized DESI-tandem MSI (MS/MSI). DON was primarily localized in the bran, endosperm side of the germ, and crease, whereas it was less prevalent in the endosperm. This distribution suggests that the cuticular layer or the plant’s dynamic defense mechanisms─such as enzymatic glycation─may impede the invasion and expansion of Fusarium into the endosperm. This spatial information, coupled with the DESI-MS/MSI analysis, may facilitate the production of flour with lower DON contamination during the milling process.

In the present study, for valuable utilization, longan seed was utilized as a matrix to establish a packaging film with tea polyphenols, and its properties and preservation action were further determined. With addition of tea polyphenols, the elongation at break of longan seed film were improved (from 12.0 to 14.6%). Meanwhile, the thermal stability, antioxidant capability, water vapor permeability (from 2.42 to 1.33 × 10^–10 g·m^–1·s^–1·Pa^–1), and oxygen permeability (from 2.79 to 2.64 × 10^–16 g·m^–1·s^–1·Pa^–1) of longan seed film were ameliorated with tea polyphenols. By using fresh-cut apples as a model, longan seed film with tea polyphenols exhibited significant inhibition on the enzymatic browning of the fresh-cut apples during storage. Furthermore, it inhibited the decrease of total phenol content and increase of soluble solid content of fresh-cut apples. All results suggest that the longan seed film with tea polyphenols shows the potential to protect the freshness of fruits and vegetables in the food industry.

Vegetable and fruit chips may carry a risk of containing trace amounts of acrylamide, which is a probable carcinogen. Hence, this study presents a sensitive method for the identification and quantification of acrylamide in chips. The finely pulverized sample is mixed with ultrapure water and defatted with hexane. The aqueous extract is then brominated, and the derivatized acrylamide is extracted and preconcentrated using a small volume of low-density anisole through dispersive liquid–liquid microextraction. The aqueous phase is subjected to freezing, and the organic layer is separated by decanting. The organic phase is subsequently treated with triethylamine before being analyzed using gas chromatography–mass spectrometry. The method has a limit of detection of 0.2 μg/L, a relative standard deviation of less than 7%, and recoveries of spiked samples ranging from 84 to 102%. The method was applied to determine the acrylamide content in potato, taro, durian, jackfruit, and banana chips. The values ranged from 41 to 2940 μg/kg. Banana chips contained the lowest acrylamide content, while jackfruit chips had the highest.