Perennial fruit crops enter dormancy to ensure bud tissue survival during winter. However, a faster phenological advancement caused by global warming exposes bud tissue to a higher risk of spring frost damage. Tissue dehydration and soluble sugars accumulation are connected to freezing tolerance, but non-structural carbohydrates also act as metabolic substrates and signaling molecules. A deepened understanding of sugar metabolism in the context of winter freezing resistance is required to gain insight into adaptive possibilities to cope with climate changes. In this study, the soluble sugar content was measured in a cold-tolerant grapevine hybrid throughout the winter season. Moreover, the expression of drought-responsive hexose transporters VvHT1 and VvHT5, raffinose synthase VvRS and grapevine ABA-, Stress- and Ripening protein VvMSA was analyzed. The general increase in sugars in December and January suggests that they can participate in protecting bud tissues against low temperatures. The modulation of VvHT5, VvINV and VvRS appeared consistent with the availability of the different sugar species; challenging results were obtained for VvHT1 and VvMSA, suggesting interesting hypotheses about their role in the sugar–hormone crosstalk. The multifaceted role of sugars on the intricate phenomenon, which is the response of dormant buds to changing temperature, is discussed.

The possible contribution of brine-derived microflora to the sensory attributes of cheese is still a rather unexplored field. In this study, 365 bacteria and 105 yeast strains isolated from 11 cheese brines were qualitatively tested for proteolytic and lipolytic activities, and positive strains were identified by sequencing. Among bacteria, Staphylococcus equorum was the most frequent, followed by Macrococcus caseolyticus and Corynebacterium flavescens. As for yeasts, Debaryomyces hansenii, Clavispora lusitaniae, and Torulaspora delbrueckii were most frequently identified. 38% of bacteria and 59% of yeasts showed at least one of the metabolic activities tested, with the lipolytic activity being the most widespread (81% of bacteria and 95% of yeasts). Fifteen strains of bacteria and 10 yeasts were inoculated in a curd-based medium and assessed by HS-SPME-GC-MS to determine their volatilome. After a 30-d incubation at 12°C, most strains showed a viability increase of about 2 log cfu/mL, suggesting good adaptability to the cheese environment. Twenty-six compounds were detected in the headspace, carbonyl compounds and alcohols being the major contributors to the volatile profile of the curd-based medium. Multivariate analysis was carried out to elucidate the overall differences in volatiles produced by selected strains. PCA and hierarchical clustering analysis demonstrated that the brine-related microorganisms were separated into 3 different groups, suggesting their different ability to produce volatile compounds. Some of the selected strains have shown to have an interesting aromatic potential and to possibly contribute to the sensory properties of cheese.

Volatile organic compounds (VOCs) produced by yeasts can positively affect crops, acting as antifungals or biostimulants. In this study, Aureobasidium pullulans and Metschnikowia pulcherrima were evaluated as potential antagonists of Trichoderma spp., common fungal pathogen in mushroom cultivation. To assess the biocontrol ability and biostimulant properties of the selected yeast species, in vitro co-culture and VOCs exposure assays were conducted. In both assays, VOCs produced by Aureobasidium spp. showed the stronger antifungal activity with a growth inhibition up to 30 %. This result was further confirmed by the higher volatilome alcohol content revealed by solid phase microextraction-gas chromatography mass spectrometry (SPME/GC–MS). Overall, Aureobasidium strains can be potentially used as biocontrol agent in Pleorotus ostreatus and Cyclocybe cylindracea mycelial growth, without affecting their development as demonstrated by VOCs exposure assay and Fourier-transform infrared spectroscopy (FT-IR). Conversely, M. pulcherrima was characterized by a lower or absent antifungal properties and by a volatilome composition rich in isobutyl acetate, an ester often recognized as plant growth promoter. As confirmed by FT-IR, Lentinula mycelia exposed to M. pulcherrima VOCs showed a higher content of proteins and lipids, suggesting an improvement of some biochemical properties. Our study emphasizes that VOCs produced by specific yeast strains are potentially powerful alternative to synthetic fungicide in the vegetative growth of mushroom-forming fungi and also able to modify their biochemical composition.

Seven mango seeds of Ivorian varieties, that is, Amelie, Kent, Keitt, Brooks, Palmer, Dadiani, and Djakoumankoun were collected from Northern Ivory Coast as wastes from local processing factories and local markets; their kernels were then quickly separated and sun‐dried to ensure lipases inactivation. This study was carried out to elucidate (1) the variability in the proximate composition (protein, ash, and fat content) of the so‐obtained kernels and (2) the characteristics of the extracted fat including acidity, peroxide value, unsaponifiable matters, phospholipid content, iodine value, fatty acid (FA), and triacylglycerol (TAG) composition, sterol content, oxidative stability, color, and carotenoid content. It was found that the fat content ranged from 4.9% to 9.6% (dry matter) depending on the variety. Whatever the variety, oleic (O, 35.9%–47%) and stearic acid (St, 30.3%–48.3%) were the most abundant FA. A wide range of variation in TAG composition was however observed: the major were StOSt (23.9%–45.9%), StOO (15.5%–25.8%), and StLSt (10.4%–12.5%). A classification of the seven varieties based on their FA, TAG, and sterol content, was established using multivariate analysis: principal component analysis (PCA) and cluster analysis (CA). According to their main FA and TAG, the seven varieties may be grouped into four clusters: cluster I = Amelie, cluster II = Keitt, Palmer, and Kent, cluster III = Brooks and Dadiani and, cluster IV = Djakoumankoun.