Characterization of the Volatile Compounds of Onion with Different Fresh-Cut Styles and Storage Temperatures

Effects of different preparation and cooking processes on the bioactive molecules of Allium vegetables

Allium species are among the most widely cultivated vegetables for centuries for their positive effects on human health and their variety of uses in food preparation and cooking. Preparation and cooking processes create chemical changes that can affect the concentration and bioavailability of bioactive molecules. Understanding the changes in bioactive compounds and bioactive activities in Allium vegetables resulting from preparation and cooking processes is essential for better retention of these compounds and better utilization of their health benefits. This study aimed to investigate the effects of different preparation and cooking processes on the bioactive molecules of Allium vegetables. This review concludes that bioactive compounds in Allium vegetables are affected by each preparation and cooking process depending on variables including method, time, temperature. Owing to differences in the matrix and structure of the plant, preparation and cooking processes show different results on bioactive compounds and bioactive activities for different vegetables. Continued research is needed to help fill gaps in current knowledge, such as the optimal preparation and cooking processes for each Allium vegetable.

Dental restorative materials and halitosis: a preliminaryin-vitrostudy

Despite the widespread use of dental restorative materials, little information exists in the literature regarding their potential impact on bad breath. This in vitro study aims to fill this gap by investigating the influence of different restorative materials on the release of hydrogen sulfide (H2S). Thirteen diverse dental restorative materials, including composites, flowable composites, glass ionomer restorative materials, high-copper amalgam, and CAD-CAM blocks, were examined. Cellulose Sponge models were used as negative and positive control. All samples were prepared with a diameter of 5 mm and a height of 2 mm. Except for the negative control group, all samples were embedded into Allium cepa L., and the emitted H2S was measured using the Wintact W8802 hydrogen sulfide monitor. Surface roughness's effect on emission was explored by roughening the surfaces of CAD-CAM material samples, and gas emission was measured again. The data were statistically analyzed using the Kruskal-Wallis test and DSCF pairwise comparison tests. Fiber-reinforced flowable composite (EverX Flow), amalgam (Nova 70-caps), and certain composite materials (IPS Empress Direct, Tetric Evoceram, Admira Fusion X-tra) released higher H2S concentrations compared to the negative control. The H2S release period lasted longer in the same materials mentioned above, along with G-aenial Universal Injectable. Indirectly used materials, such as GC Cerasmart, Vita Enamic, and Vita YZ HT, demonstrated significantly lower emissions compared to other direct restoratives. Importantly, the surface roughness of indirect materials did not significantly affect peak H2S concentrations or release times. The study reveals variations in H2S release among restorative materials, suggesting potential advantages of indirect restorative materials in reducing H2S-induced halitosis. This comprehensive understanding of the relationship between restorative materials and halitosis can empower both dental professionals and patients to make well-informed treatment choices. Notably, there is evidence supporting the enhanced performance of indirect restorative materials for individuals affected by halitosis.

Non-volatile and volatile compound changes in blueberry juice inoculated with different lactic acid bacteria strains

BACKGROUND

Lactic acid bacteria (LABs) are widely present in foods and affect the flavour of fermented cultures. This study investigates the effects of fermentation with Lactobacillus acidophilus JYLA-16 (La), Lactobacillus plantarum JYLP-375 (Lp), and Lactobacillus rhamnosus JYLR-005 (Lr) on the flavour profile of blueberry juice.

RESULTS

This study showed that all LABs strains preferentially used glucose rather than fructose as the carbon source during fermentation. Lactic acid was the main fermentation product, reaching 7.76 g L-1 in La-fermented blueberry juice, 5.86 g L-1 in Lp-fermented blueberry juice, and 6.41 g L-1 in Lr-fermented blueberry juice. These strains extensively metabolized quinic acid, whereas oxalic acid metabolism was almost unaffected. Sixty-four volatile compounds were identified using gas chromatography-ion mobility spectrometry (GC-IMS). All fermented blueberry juices exhibited decreased aldehyde levels. Furthermore, fermentation with La was dominated by alcohols, Lp was dominated by esters, and Lr was dominated by ketones. Linear discriminant analysis of the electronic nose and principal component analysis of the GC-IMS data effectively differentiated between unfermented and fermented blueberry juices.

CONCLUSION

This study informs LABs selection for producing desirable flavours in fermented blueberry juice and provides a theoretical framework for flavour detection. © 2023 Society of Chemical Industry.

Early Detection of Fusarium Basal Rot Infection in Onions and Shallots Based on VOC Profiles Analysis

Gas chromatography ion-mobility spectrometry (GC-IMS) technology is drawing increasing attention due to its high sensitivity, low drift, and capability for the identification of compounds. The noninvasive detection of plant pests and pathogens is an application area well suited to this technology. In this work, we employed GC-IMS technology for early detection of Fusarium basal rot in brown onion, red onion, and shallot bulbs and for tracking disease progression during storage. The volatile profiles of the infected and healthy control bulbs were characterized using GC-IMS and gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). GC-IMS data combined with principal component analysis and supervised methods provided discrimination between infected and healthy control bulbs as early as 1 day after incubation with the pathogen, classification regarding the proportion of infected to healthy bulbs in a sample, and prediction of the infection's duration with an average R2 = 0.92. Furthermore, GC-TOF-MS revealed several compounds, mostly sulfides and disulfides, that could be uniquely related to Fusarium basal rot infection.

Comparison of the volatile organic compounds in Citrus reticulata 'Chachi' peel with different drying methods using E-nose, GC-IMS and HS-SPME-GC-MS

Introduction

Citrus reticulata 'Chachi' peel (CRCP), which is named "Guangchenpi" in China, is a geographical indication product with unique flavor properties. CRCP has been used for centuries as a traditional genuine herb because of its excellent therapeutic effects. In addition, owing to its unique odor and high nutrition, it is widely used in various food preparations. Volatile organic compounds (VOCs) are regarded as an important quality marker for CRCP and are highly susceptible to effects in the drying process due to their thermal instability.

Methods

In the current study, the main VOCs in CRCP were processed using different drying methods, including sun-drying, hot air drying, and vacuum-freeze drying. The VOCs were identified by the electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS).

Results

The results showed that the CRCP dried by vacuum-freeze exhibited the highest VOCs contents and retained the richest compounds compared to those dried by other methods, which indicated that vacuum-freeze drying is the most suitable for CRCP production. Furthermore, the chemometrics analysis revealed that the primary differential metabolites of the samples generated using different drying methods were terpenes and esters.

Discussion

Overall, our study would help better understand the VOCs present in CRCP with different drying methods. The outcomes of the current study would guide the drying and processing of CRCP, which is beneficial for large-scale storage and industrial production of CRCP.