Department of Wine, Food and Molecular Biosciences

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The Department of Wine, Food and Molecular Biosciences covers course areas including animal and plant science, biochemistry, food science, horticulture, microbiology, sensory science, viticulture and wine science.

Recent Submissions

Now showing 1 - 5 of 835
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    Comparative genome identification of accessory genes associated with strong biofilm formation in Vibrio parahaemolyticus
    (Elsevier, 2023-04) Wang, D; Fletcher, GC; Gagic, D; On, Stephen; Palmer, JS; Flint, SH
    Vibrio parahaemolyticus biofilms on the seafood processing plant surfaces are a potential source of seafood contamination and subsequent food poisoning. Strains differ in their ability to form biofilm, but little is known about the genetic characteristics responsible for biofilm development. In this study, pangenome and comparative genome analysis of V. parahaemolyticus strains reveals genetic attributes and gene repertoire that contribute to robust biofilm formation. The study identified 136 accessory genes that were exclusively present in strong biofilm forming strains and these were functionally assigned to the Gene Ontology (GO) pathways of cellulose biosynthesis, rhamnose metabolic and catabolic processes, UDP-glucose processes and O antigen biosynthesis (p < 0.05). Strategies of CRISPR-Cas defence and MSHA pilus-led attachment were implicated via Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Higher levels of horizontal gene transfer (HGT) were inferred to confer more putatively novel properties on biofilm-forming V. parahaemolyticus. Furthermore, cellulose biosynthesis, a neglected potential virulence factor, was identified as being acquired from within the order Vibrionales. The cellulose synthase operons in V. parahaemolyticus were examined for their prevalence (22/138, 15.94 %) and were found to consist of the genes bcsG, bcsE, bcsQ, bcsA, bcsB, bcsZ, bcsC. This study provides insights into robust biofilm formation of V. parahaemolyticus at the genomic level and facilitates: identification of key attributes for robust biofilm formation, elucidation of biofilm formation mechanisms and development of potential targets for novel control strategies of persistent V. parahaemolyticus.
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    Synthesis of β-cyclodextrin@gold nanoparticles and its application on colorimetric assays for ascorbic acid and salmonella based on peroxidase-like activities
    (MDPI, 2024-03-31) Fan, X; Bao, Y; Chen, Y; Wang, X; On, Stephen; Wang, J
    The peroxidase-like behaviors of gold nanoparticles (AuNPs) have the potential to the development of rapid and sensitive colorimetric assays for specific food ingredients and contaminants. Here, using NaBH₄ as a reducing agent, AuNPs with a supramolecular macrocyclic compound β-cyclodextrin (β-CD) capped were synthesized under alkaline conditions. Monodispersal of β-CD@AuNPs possessed a reduction in diameter size and performed great peroxidase-like activities toward both substrates, H₂O₂ and TMB. In the presence of H₂O₂, the color change of TMB oxidization to oxTMB was well-achieved using β-CD@AuNPs as the catalyst, which was further employed to develop colorimetric assays for ascorbic acid, with a limit of detection as low as 0.2 μM in ddH₂O. With the help of the host-guest interaction between β-CD and adamantane, AuNPs conjugated with nanobodies to exhibit peroxidase-like activities and specific recognition against Salmonella Typhimurium simultaneously. Based on this bifunctional bioprobe, a selective and sensitive one-step colorimetric assay for S. Typhimurium was developed with a linear detection from 8.3 × 10⁴ to 2.6 × 10⁸ CFU/mL and can be provided to spiked lettuce with acceptable recoveries of 97.31% to 103.29%. The results demonstrated that the excellent peroxidase-like behaviors of β-CD@AuNPs can be applied to develop a colorimetric sensing platform in the food industry.
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    Efficacy of commercial peroxyacetic acid on Vibrio parahaemolyticus planktonic cells and biofilms on stainless steel and Greenshell™ mussel (Perna canaliculus) surfaces
    (Elsevier, 2023-11-16) Wang, D; Palmer, JS; Fletcher, GC; On, Stephen; Gagic, D; Flint, SH
    The potential of using commercial peroxyacetic acid (PAA) for Vibrio parahaemolyticus sanitization was evaluated. Commercial PAA of 0.005 % (v/v, PAA: 2.24 mg/L, hydrogen peroxide: 11.79 mg/L) resulted in a planktonic cell reduction of >7.00 log₁₀ CFU/mL when initial V. parahaemolyticus cells averaged 7.64 log₁₀ CFU/mL. For cells on stainless steel coupons, treatment of 0.02 % PAA (v/v, PAA: 8.96 mg/L, hydrogen peroxide: 47.16 mg/L) achieved >5.00 log₁₀ CFU/cm² reductions in biofilm cells for eight strains but not for the two strongest biofilm formers. PAA of 0.05 % (v/v, PAA: 22.39 mg/L, hydrogen peroxide: 117.91 mg/L) was required to inactivate >5.00 log₁₀ CFU/cm² biofilm cells from mussel shell surfaces. The detection of PAA residues after biofilm treatment demonstrated that higher biofilm production resulted in higher PAA residues (p < 0.05), suggesting biofilm is acting as a barrier interfering with PAA diffusing into the matrices. Based on the comparative analysis of genomes, robust biofilm formation and metabolic heterogeneity within niches might have contributed to the variations in PAA resistance of V. parahaemolyticus biofilms.
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    Effects of repeated tasting sessions on acceptability, emotional responses, and purchasing behaviors of waste-to-value-addedSCOBY (symbiotic culture of bacteria and yeast) ice cream
    (Wiley Periodicals LLC., 2024-04) Mehta, A; Serventi, Luca; Kumar, Lokesh; Torrico, Damir
    This study investigated the effects of repeated exposure on acceptability, emotional responses, and purchase intention of a novel symbiotic culture of bacteria and yeast (SCOBY) ice cream, compared to a control (no extra additives) and a guar gum ice cream sample, using three sessions: a survey (SCOBY information) and two tasting sessions (repeated-exposure effect). Participants initially conducted blind evaluations of all samples, followed by an informed tasting. The blind tasting sessions evoked high arousal emotions for the SCOBY ice cream and positive emotions for the control and guar gum samples. The second session showed a rise in liking for sweetness (5.6–6.5) and texture (5.6–6.7) of the SCOBY samples. Sensory attributes such as flavor (odds ratio = 1.7) and texture (odds ratio = 1.7), coupled with positive emotions such as “happy” (odds ratio = 3.8), “pleasant” (odds ratio = 0.4), and “interested” (odds ratio = 3.8) affected purchase intention. The findings of this study provide valuable insights into participants' liking and emotional responses during repeated exposures to stimuli. Practical Applications: The study's findings show that repeated exposure to novel products enhances consumer acceptance and emotional responses, challenging the current formats of traditional sensory studies. This implies that the introduction of novel products can be successful with repeated tasting exposure strategies. The focus on improving familiarity with sensory attributes, especially flavor and texture, can positively impact purchase intention. This insight can guide product positioning, marketing campaigns, and flavor development efforts, encouraging the successful integration of innovative products into the market.
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    Wine aromas
    (MDPI, 2023-12) Tian, Bin; Zhang, J
    Wine has a complex matrix with many volatile compounds present, which evolves over time. These volatile compounds are important to wine quality as they contribute to the aroma and varietal characteristics of wine. Recent development in the analysis of volatile compounds in wine has greatly improved our understanding of the complexity of wine aroma. Analytical methods used for wine aroma fingerprinting have shown potential in determining the origin and quality of wine. Thus, research on volatile compounds responsible for wine aroma and their correlation with wine provenance and wine quality have increasingly attracted great interest from researchers and winegrowers. This Special Issue presents the latest research regarding wine aroma compounds, including, but not limited to, the topics on the characterization of aroma compounds in grapes and wine, factors influencing the production of aroma compounds in wine during fermentation and maturation, and analytical methods for wine aroma analysis.