Journal of Food Science最新文献

Although recent studies have reported the presence of a variety of bacteria in guarana products, particularly in beverages from soda fountain machines, investigations into microbial behavior in the guarana production chain remain limited. This study evaluated the fitness and microbial growth of bacterial isolates from guarana-based products and by-products. The behavior of seventeen isolates (Enterococcus hirae LMQA-PG1 and LMQA-PG2, Klebsiella pneumoniae LMQA-PG4, Klebsiella variicola LMQA-PG4.2, Cronobacter sp LMQA-PG3.2, LMQA-PG4.1, and LMQA-PG4.2, Bacillus cereus LMQA-PG9.1, LMQA-PG2.1, and LMQA-PG3.1, Enterobacter cloacae LMQA-PG3.3, LMQA-PG3.1, and LMQA-PG4.1, Pseudomonas aeruginosa LMQA-PG1.2, and LMQA-PG1.3, Escherichia hermannii LMQA-PG4.3, and Salmonella sp. LMQA-AF3) were assessed under different pH (3 to 7), temperature (2–55°C), and water activity (a_w) (0.500 to 0.919). Most isolates showed high growth performance when cultivated at 25–42°C and pH 6–7, but were inhibited under extreme conditions, including temperatures of 2, 10, and 55°C, acidic pH values of 3-3.5, and all a_w tested. Several isolates exhibited enzymatic activities with proteolytic and lipolytic spoilage potential, particularly Bacillus cereus, and resistance to more than two antimicrobial agents. Based on fitness performance, eight representative isolates (from Enterococcus, Klebsiella, Cronobacter, Bacillus cereus, Enterobacter, Pseudomonas, Escherichia hermannii, and Salmonella) were then tested in six guarana beverage matrices, three reconstituted guarana-flavored powdered refreshments, and three ready-to-drink guarana refreshments. None of the beverages stored at 30 or 37°C for microbial growth supported bacterial growth, with reductions up to 6 log UFC/mL observed in reconstituted formulations (pH 3.01–3.29).

Practical Applications

This study demonstrated that all brands of reconstituted guarana-flavored powdered (pH 3.12) and ready-to-drink guarana refreshment (pH 3.31) beverages investigated inhibited the microbial growth of bacteria isolated from guarana products and production residues.

Phlorotannins have gained significant attention for their potential bioactive and functional properties. However, these compounds are highly sensitive to gastrointestinal digestion, which limits their bioavailability and consequently the in vivo efficacy.

To address this limitation, this study explored the use of various concentrations of γ- and β-cyclodextrins in the aqueous microwave-assisted extraction of phlorotannins from Fucus vesiculosus and submitted the resulting extracts to an in vitro gastrointestinal digestion protocol.

While higher cyclodextrin concentrations resulted in an increase in extraction yields (from 47% to approximately 55% for both cyclodextrins), the opposite was observed for the total phlorotannin content. Notably, higher cyclodextrin concentrations markedly improved phlorotannin stability across the different stages of gastrointestinal digestion. Specifically, β-cyclodextrin exhibited the highest protective effect, preventing phlorotannin degradation almost completely in both oral and gastric phases, and retaining approximately 35% (approximately 1.0 mg/g extract) of the initial content (approximately 3.0 mg/g extract) after the intestinal phase, thereby enhancing the compounds’ resistance and residence time in the intestinal lumen. A comparison between the addition of β-cyclodextrin during extraction and post-extraction revealed that, although both approaches reduce the phlorotannin loss throughout the gastrointestinal tract, the β-cyclodextrin-assisted extraction showed better efficacy. This indicates that strong guest-host interactions are formed between phlorotannins and cyclodextrins during the extraction, possibly due to the increased enthalpy generated by microwave heating.

Overall, this study highlights β-cyclodextrin-microwave-assisted extraction as a promising approach to enhance the stability of phlorotannins in their transit through the gastrointestinal tract, ensuring their delivery to the intestinal lumen, where they can be released and available for absorption.

In this study, a non-Korean kimchi formulated with the unconventional ingredient sea fennel (Crithmum maritimum L.) was investigated under both spontaneous and starter-driven fermentation to assess microbial composition and dynamics. Metataxonomic analyses revealed significant differences between starter-inoculated and control (spontaneously fermented) kimchi. Weissella koreensis and members of the genus Companilactobacillus dominated the control samples, whereas Levilactobacillus spp., Lactiplantibacillus plantarum, and Pediococcus pentosaceus prevailed in the starter-inoculated kimchi. Fungal community profiling consistently showed the dominance of the genus Alternaria throughout fermentation in both prototypes. Kazachstania servazzi became abundant at late fermentation in both kimchi types, while Saccharomyces cerevisiae appeared exclusively in the control samples during mid-fermentation. Isolation of lactic acid bacteria provided further insights into active microbial populations across fermentation stages. W. koreensis and Leuconostoc mesenteroides were the most frequently detected species. The isolates displayed considerable heterogeneity in enzymatic activity profiles: strong leucine arylamidase and β-glucosidase activities were identified, both potentially influencing kimchi's sensory traits. Importantly, no β-glucuronidase activity was detected, suggesting safety of the isolates with respect to cancer-associated risks. Conversely, three isolates carried the hdcA gene, and none exhibited bacteriocin activity against Listeria innocua (used as a surrogate for Listeria monocytogenes). Most isolates demonstrated robust growth and activity in a kimchi-like medium, underscoring their performance as starter or adjunct cultures for guided fermentation of kimchi.

Practical Applications

This scientific research used DNA-based microbial profiling to identify high technological lactic acid bacteria that can serve as starter cultures for guided kimchi fermentation. These findings may help producers create safe, more consistent, and high-quality fermented vegetables for global markets.

One of the leading hypotheses of plant protein texturization during extrusion is the formation of disulfide bonds during the extrusion process. This study aimed to gain a deeper understanding of the role of disulfide bonds during the texturization of plant protein high moisture meat analogs. Pea protein was blended with three reducing agents, sodium metabisulfite, cysteine, and glutathione, at varying levels of inclusion. The blends were extruded using a co-rotating twin-screw extruder at two different temperature settings of 130°C and 150°C. The feed rate (60 g/min), screw speed (100 rpm), and moisture content (60% w.b.) were kept constant. The extrudates were evaluated for polymeric protein size exclusion, disulfide, and thiol bond quantification, integrity index analysis, and anisotropic index. The reducing agents cleaved disulfide bonds and significantly affected the structure, texture, and integrity index of the extrudates. The reducing agents also had varying effects on the extrudate and the flow of the melt, with the best product obtained with 0.05% glutathione inclusion extruded at 150°C. Although the reducing agents had a relatively small impact on the disulfide bonds, they had a major impact on the physical characteristics of the product and the crosslinking of proteins.

This study aimed to investigate the hepatoprotective effects and underlying mechanisms of a peptide-plant extract combination against alcohol-induced liver injury in a zebrafish model. The results demonstrate that wheat peptides (WP), soft-shelled turtle peptides (STP), and Pueraria lobata root extract (PE) significantly attenuate hepatomegaly and lipid droplet accumulation, enhance the activities of acetaldehyde dehydrogenase (ALDH) and superoxide dismutase (SOD), and decrease the levels of aspartate aminotransferase (AST) and malonaldehyde (MDA). The optimal formulation ratio of WP, STP, and PE (1:4:1) is determined using fuzzy comprehensive evaluation (FSE). The combination significantly down-regulated the expression of the alcohol-metabolism-related genes cytochrome P450 2Y3, cytochrome P450 (CYP)(cyp2y3) and cytochrome P450CYP3A65 (cyp3a65), the fatty acid synthesis-related gene acetyl-CoA carboxylase 1 (acc1), and DNA damage-inducing gene 153 (GADDl53) (chop). Furthermore, the combination improves gut microbiota diversity, increases the relative abundance of Chitinilyticum, and decreases that of ZOR006 and Erysipelotrichaceae. Non-targeted metabolomics analysis reveals that the hepatoprotective effect is primarily mediated through by up-regulating of nucleotide and pyrimidine metabolism pathways, thereby maintaining cellular energy homeostasis. In addition, the combination up-regulates ZO-1 and Nrf-2 expression, contributing to the restoration of alcohol-induced intestinal barrier integrity. Collectively, the optimized peptide–plant extract formulation confers significant protection against alcohol-induced liver injury by modulating gut microbiota composition, re-establishing hepatic metabolic homeostasis, and reinforcing intestinal barrier function.

Iron deficiency in children is a persistent global public health problem. This study evaluated the efficacy of an extruded rice matrix as a carrier for micronized dispersible ferric pyrophosphate (MDFP), aiming to increase iron bioavailability in traditional rice-based desserts formulated with cow's milk (CM) or soy soluble protein extract (SSPE). Four experimental diets were administered to the rats: (i) fortified with CM and MDFP incorporated into extruded rice; (ii) fortified with SSPE and MDFP incorporated into extruded rice; (iii) control with ferrous sulfate (AIN-93G); and (iv) a control with pure MDFP (AIN-93G). Both fortified groups showed significantly higher recovery of iron nutritional status (p < 0.05), demonstrating that the different liquid ingredients did not compromise iron bioavailability. Gene expression analyses of key iron metabolism proteins (DMT-1, DcytB, ferroportin, hephaestin, transferrin, and ferritin) confirmed that the extruded rice matrix increased the bioavailability of MDFP compared to the compound in its pure form (p < 0.05), possibly reducing aggregation and favoring direct interaction with intestinal absorption sites. Furthermore, the fortified formulations demonstrated satisfactory sensory acceptance among school-ageRd children. These results indicate that incorporating MDFP into an extruded rice is an effective and technologically viable strategy for developing fortified rice desserts, with potential application in programs to combat iron deficiency anemia, specially in schoo-laged children at poor regions worldwide.

Practical Applications

Rice desserts fortified with micronized ferric pyrophosphate (MDFP) in an extruded rice matrix effectively improved iron availability without diminish sensory acceptance by children. Hence, the technology here reported offers a practical, low-cost strategy for school feeding programs as well as for food industry to develop fortified products to fight against iron deficiency anemia.

The aim of this study was to explore the effects of Lacticaseibacillus rhamnosu AFY02 (LR-AFY02), which was obtained from traditional fermented yogurt, on mice with inflammation-related AOM/DSS-induced colon cancer and the associated processes. The pathological results of the colon tissue of mice, the indicators of serum and tissue, and their expressions in the tissue were detected. The results showed that the use of LR-AFY02 significantly improved intestinal histopathological injury, decreased the incidence of intestinal tumors, downregulated the expression of IκBβ, p65, p50, p52, Bcl-2, and Bcl-xL in colon tissue, and increased the expression of Bid and caspase-8 in colon tissue. Compared with the model group, high concentration LR-AFY02H could reduce IL-1β, IL-6, TNF-α, NF-κB, and iNOS cytokine levels in serum and colon tissue. The ability to downregulate these cytokines was close to that of aspirin and stronger than that of low concentration LR-AFY02L. By controlling the NF-κB and apoptosis pathways, LR-AFY02 can help reduce intestinal inflammation and prevent the growth of intestinal tumors. These findings suggested that LR-AFY02 may have regulatory effects on colon cancer in mice and merits additional study.

ABSTRACT

Ginger oil, a global commodity rich in diverse mono- and sesquiterpenes, is largely used as the natural flavor, therapeutic, and cosmetic ingredient. This study aimed to investigate the impact of conventional size-reduction techniques (9, 6, and 3 mm slicing, crushing, grating, and grinding) of fresh ginger on its oil and analogize it in ginger tea volatile flavors. A decrease in particle size elevated the oil yield and critically impacted the oil composition. The finer size enhanced the yield of sesquiterpene hydrocarbons (grated/9-mm slices: 8.0–19.0), thus elevating their concentrations (grated/9-mm slices: 2.8–7.7) and overall oil productivity. Their extraction was ineffective, hence incomplete, from thick slices, which improved upon size reduction. However, a reverse trend was observed for the levels of oxygenated monoterpenes (9-mm slices/grated: 1.5–4.1). The extractability and yield of these monoterpenes were maintained throughout, thus reducing their concentrations with decreasing particle size due to an elevated oil productivity. Utilizing this knowledge, a hydrodistillation-based two-step process was developed, enriching sesquiterpene hydrocarbons and oxygenated monoterpenes separately in two oil fractions. Also, the quantity of these volatile flavors in ginger tea followed a similar trend with traditional size-reduction methods (dicing, crushing, and grating). The amount of major sesquiterpene hydrocarbons was elevated by 3.6–9.3 times in the tea of grated ginger compared to diced, while oxygenated monoterpenes maintained a narrow range. Thus, the current study quantitatively correlated size-reduction methods with the volatile flavors in ginger oil and tea. This knowledge will be useful for the efficient hydrodistillation of fresh ginger or enrichment of major terpene classes thereof.

The lung and gut were a pair of related organ systems, and the study aimed to investigate the lung protection of Houttuynia cordata Thunb. essential oil (HEO) on gut–lung crosstalk in lipopolysaccharide-induced acute lung injury (ALI) rats. Animal results showed that HEO performed lung protection by alleviating lung histopathological changes. Moreover, gut–lung interaction was shown during HEO-exerted lung protection, evidenced by overlap between lung and gut on correcting inflammatory profile through suppressing serum IL-1β and TLR4/NF-κB p65 signaling, suggesting that the intestine could behave as a “social” capacity to protect distal lung via gut–lung interaction. Furthermore, HEO was demonstrated to strengthen the intestinal barrier by elevating Zonula occludens-1 and inhibiting NLRP3 inflammasome through interfering with mitochondria–endoplasmic reticulum contacts through decreasing mitofusin 2, and its intestinal protection was also confirmed in cell experiments. Subsequently, 16S rRNA sequencing revealed that HEO significantly restored gut microbiota dysbiosis and increased short-chain fatty acids, which was in parallel with attenuation of metabolic abnormalities via UPLC-Q-TOF/MS-based serum metabolomics. Metabolomic analysis suggested that tryptophan metabolism was identified to be one of the critical pathways in gut–lung communication, which could be traced to Bacteroides and Lactobacillus in ALI rats exposed to HEO, concluding that lung protection of HEO could be driven by microbiota–gut–lung axis.

The problem of swollen canned Hubei broad bean paste, a traditional fermented food, leads to significant quality degradation and economic loss. This study aimed to isolate and identify the causative gas-producing bacterium and develop an effective control strategy. A dominant strain, designated Clostridium tyrobutyricum strain LG12 (accession number MT265221.1), was isolated from swollen cans and identified via 16S rDNA sequencing. Physiological studies revealed that this isolate grew optimally at neutral-acidic pH (5–7) and exhibited high heat tolerance, surviving after 20 min of treatment at 100°C. It also showed notable salt tolerance, withstanding up to 10% NaCl. Traceability analysis confirmed that this bacterium originated from the fermented chili, a primary raw material. The efficacy of nisin, ε-polylysine hydrochloride (ε-PL HCl), and sodium diacetate in inhibiting its growth was evaluated in vitro. An optimized combination (nisin 50 mg/L, ε-PL HCl 500 mg/L, sodium diacetate 1250 mg/L) was found to inhibit bacterial growth by over 99%. Finally, this combination was validated in the Hubei broad bean paste system, where it effectively prevented package swelling, offering a practical solution for the industry.