This work aimed to examine the effects of sex on meat and fat quality traits from thirty Portuguese Alentejano (AL) pigs reared in outdoor conditions. These pigs were divided into three groups and fed ad libitum. From ~40 to 130 kg LW, castrated (C group) and intact animals (I and IExp) consumed commercial diets. Until slaughter (~160 kg), C and I pigs remained on commercial diets, and IExp changed to a more sustainable experimental diet with locally produced pulses and byproducts. Samples were collected from the Longissimus lumborum (LL), Psoas major (PM), and dorsal subcutaneous fat (DSF). At ~160 kg, the PM muscle of intact pigs presented lower intramuscular fat content than that of C pigs, while total collagen was higher. Additionally, PM myoglobin was lower and lightness (L*) was higher in intact pigs. Regarding DSF, moisture and total protein contents were higher and total lipids were lower in intact than in castrated pigs, while color parameters were not significantly different. Finally, antioxidant capacity measured in the LL muscle showed an overall lower value in intact pigs. However, lipid oxidation values were not significantly different between the experimental groups and only increased with storage time. Outdoor-reared intact AL pigs produced leaner and less saturated pork and fat compared to castrated ones. Despite the lower antioxidant activity observed in the LL muscles of intact pigs, the lipid oxidative stability of cooked meat was not different among the experimental groups.
Grapes' infection by phytopathogenic fungi may often lead to rot and impair the quality and safety of the final product. Due to the concerns associated with the extensive use of chemicals to control these fungi, including their toxicity for environment and human health, bio-based products are being highly preferred, as eco-friendlier and safer alternatives. Specifically, yeasts have shown to possess antagonistic activity against fungi, being promising for the formulation of new biocontrol products.In this work 397 wine yeasts, isolated from Portuguese wine regions, were studied for their biocontrol potential against common grapes phytopathogenic fungal genera: Aspergillus, Botrytis, Mucor and Penicillium. This set comprised strains affiliated to 32 species distributed among 20 genera. Time-course monitoring of mold growth was performed to assess the inhibitory activity resulting from either diffusible or volatile compounds produced by each yeast strain. All yeasts displayed antagonistic activity against at least one of the mold targets. Mucor was the most affected being strongly inhibited by 68% of the tested strains, followed by Botrytis (20%), Aspergillus (19%) and Penicillium (7%). More notably, the approach used allowed the detection of a wide array of yeast-induced mold response profiles encompassing, besides the decrease of mold growth, the inhibition or delay of spore germination and the complete arrest of mycelial extension, and even its stimulation at different phases. Each factor considered (taxonomic affiliation, mode of action and fungal target) as well as their interactions significantly affected the antagonistic activity of the yeast isolates. The highest inhibitions were mediated by volatile compounds. Total inhibition of Penicillium was achieved by a strain of Metschnikowia pulcherrima, while the best performing yeasts against Mucor, Aspergillus and Botrytis, belong to Lachancea thermotolerans, Hanseniaspora uvarum and Starmerella bacillaris, respectively. Notwithstanding the wide diversity of yeasts tested, only three strains were found to possess a broad spectrum of antagonistic activity, displaying strong or very strong inhibition against the four fungal targets tested. Our results confirm the potential of wine yeasts as biocontrol agents, while highlighting the need for the establishment of fit-for-purpose selection programs depending on the mold target, the timing, and the mode of application.
"Queijo de Évora" is a traditional Portuguese cheese from raw ewe's milk and granted with PDO label. It is ripened traditionally in rooms with empirical control of temperature and humidity. Nowadays, almost all cheese factories use rooms with temperature and humidity control, but still a significant heterogeneity among cheeses is acknowledged due to unequal distribution of environmental conditions. This paper discusses the influence of the environmental conditions on the ripening of Queijo de Évora, including the application of computational fluid dynamics in steady state conditions. Experimental data was obtained in cheeses ripened along the traditional ripening cycle, in different locations. A significant influence of environmental conditions was observed, especially air velocity and humidity, affecting physical-chemical, microbiological and sensory characteristics. Locations with higher air velocity, presented cheeses with lower moisture content, higher mesophilic bacteria count, darker appearance and higher number of holes. Locations with higher humidity presented cheeses with lower scores on some sensorial parameters like appearance, firmness and intensity of odor. The results of computational fluid dynamics made possible the identification of areas in and around the cheese stacks were the air distribution is less than adequate or uneven, which may influence the evolution of cheese during ripening.
"Queijo de Nisa" is a traditional Portuguese cheese, granted with PDO label, produced with raw ewe's milk in which the aqueous extract of cardoon flower Cynara cardunculus L. is the only coagulant allowed. As in similar cheeses with no use of starter cultures or pasteurisation, the quality and food safety are depending on prevention, high hygienic standards and a proper manufacturing process. This study investigated the use of computer vision as novel method for the evaluation of gas holes in Queijo de Nisa in three different ripening dates (0, 15 and 35 days). A total of 48 samples were produced using cardoon flower from three different origins (C1, C2 and C3) and a commercial vegetable coagulant (C4). The results presented a high correlation between image-dependent attributes and physical-chemical properties during ripening time, especially within the first 15 days of ripening time, where major structural changes were observed inside the Queijo de Nisa cheese. Principal component analysis presented a strong correlation (p < 0.05) between image parameters and the physical-chemical evolution until 15 days. From 15 to 35 days, the evolution of cheeses was mainly depending on structural parameters, like G'1 Hz and hardness. No influence was observed due to the geographical origin of cardoon flower.
During vinification Saccharomyces cerevisiae cells are frequently exposed to high concentrations of sulfur dioxide (SO2) that is used to avoid overgrowth of unwanted bacteria or fungi present in the must. Up to now the characterization of the molecular mechanisms by which S. cerevisiae responds and tolerates SO2 was focused on the role of the sulfite efflux pump Ssu1 and investigation on the involvement of other players has been scarce, especially at a genome-wide level. In this work, we uncovered the essential role of the poorly characterized transcription factor Com2 in tolerance and response of S. cerevisiae to stress induced by SO2 at the enologically relevant pH of 3.5. Transcriptomic analysis revealed that Com2 controls, directly or indirectly, the expression of more than 80% of the genes activated by SO2, a percentage much higher than the one that could be attributed to any other stress-responsive transcription factor. Large-scale phenotyping of the yeast haploid mutant collection led to the identification of 50 Com2-targets contributing to the protection against SO2 including all the genes that compose the sulfate reduction pathway (MET3, MET14, MET16, MET5, MET10) and the majority of the genes required for biosynthesis of lysine (LYS2, LYS21, LYS20, LYS14, LYS4, LYS5, LYS1 and LYS9) or arginine (ARG5,6, ARG4, ARG2, ARG3, ARG7, ARG8, ORT1 and CPA1). Other uncovered determinants of resistance to SO2 (not under the control of Com2) included genes required for function and assembly of the vacuolar proton pump and enzymes of the antioxidant defense, consistent with the observed cytosolic and mitochondrial accumulation of reactive oxygen species in SO2-stressed yeast cells.
BACKGROUND: The introduction of yeast starter cultures consisting in a blend of Saccharomyces cerevisiae and non-Saccharomyces yeast strains is emerging for production of wines with improved complexity of flavor. The rational use of this approach is, however, dependent on knowing the impact that co-inoculation has in the physiology of S. cerevisiae. In this work the transcriptome of S. cerevisiae was monitored throughout a wine fermentation, carried out in single culture or in a consortium with Hanseniaspora guilliermondii, this being the first time that this relevant yeast-yeast interaction is examined at a genomic scale. RESULTS: Co-inoculation with H. guilliermondii reduced the overall genome-wide transcriptional response of S. cerevisiae throughout the fermentation, which was attributable to a lower fermentative activity of S. cerevisiae while in the mixed-fermentation. Approximately 350 genes S. cerevisiae genes were found to be differently expressed (FDR < 0.05) in response to the presence of H. guilliermondii in the fermentation medium. Genes involved in biosynthesis of vitamins were enriched among those up-regulated in the mixed-culture fermentation, while genes related with the uptake and biosynthesis of amino acids were enriched among those more expressed in the single-culture. The differences in the aromatic profiles of wines obtained in the single and in the mixed-fermentations correlated with the differential expression of S. cerevisiae genes encoding enzymes required for formation of aroma compounds. CONCLUSIONS: By integrating results obtained in the transcriptomic analysis performed with physiological data our study provided, for the first time, an integrated view into the adaptive responses of S. cerevisiae to the challenging environment of mixed culture fermentation. The availability of nutrients, in particular, of nitrogen and vitamins, stands out as a factor that may determine population dynamics, fermentative activity and by-product formation.
Fermentation , Hanseniaspora/metabolism , Saccharomyces cerevisiae/metabolism , Wine , Coculture Techniques , Gene Expression Profiling , Gene Expression Regulation, Fungal , Genomics , Microbial Interactions , Saccharomyces cerevisiae/genetics
Currently, pursuing yeast strains that display both a high potential fitness for alcoholic fermentation and a favorable impact on quality is a major goal in the alcoholic beverage industry. This considerable industrial interest has led to many studies characterizing the phenotypic and metabolic traits of commercial yeast populations. In this study, 20 Saccharomyces cerevisiae strains from different geographical origins exhibited high phenotypic diversity when their response to nine biotechnologically relevant conditions was examined. Next, the fermentation fitness and metabolic traits of eight selected strains with a unique phenotypic profile were evaluated in a high-sugar synthetic medium under two nitrogen regimes. Although the strains exhibited significant differences in nitrogen requirements and utilization rates, a direct relationship between nitrogen consumption, specific growth rate, cell biomass, cell viability, acetic acid and glycerol formation was only observed under high-nitrogen conditions. In contrast, the strains produced more succinic acid under the low-nitrogen regime, and a direct relationship with the final cell biomass was established. Glucose and fructose utilization patterns depended on both yeast strain and nitrogen availability. For low-nitrogen fermentation, three strains did not fully degrade the fructose. This study validates phenotypic and metabolic diversity among commercial wine yeasts and contributes new findings on the relationship between nitrogen availability, yeast cell growth and sugar utilization. We suggest that measuring nitrogen during the stationary growth phase is important because yeast cells fermentative activity is not exclusively related to population size, as previously assumed, but it is also related to the quantity of nitrogen consumed during this growth phase.
Non-Saccharomyces yeasts include different species which comprise an ecologically and biochemically diverse group capable of altering fermentation dynamics and wine composition and flavour. In this study, single- and mixed-culture of Hanseniaspora guilliermondii and Saccharomyces cerevisiae were used to ferment natural grape-juice, under two nitrogen regimes. In single-culture the strain H. guilliermondii failed to complete total sugar breakdown even though the nitrogen available has not been a limiting factor of its growth or fermentative activity. In mixed-culture, that strain negatively interfered with the growth and fermentative performance of S. cerevisiae, resulting in lower fermentation rate and longer fermentation length, irrespective of the initial nitrogen concentration. The impact of co-inoculation on the volatile compounds profile was more evident in the wines obtained from DAP-supplemented musts, characterised by increased levels of ethyl and acetate esters, associated with fruity and floral character of wines. Moreover, the levels of fatty acids and sulphur compounds which are responsible for unpleasant odours that depreciate wine sensory quality were significantly lower. Accordingly, data obtained suggests that the strain H. guilliermondii has potential to be used as adjunct of S. cerevisiae in wine industry, although possible interactions with S. cerevisiae still need to be elucidated.
Fermentation , Hanseniaspora/metabolism , Nitrogen/metabolism , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/metabolism , Wine/analysis , Wine/microbiology , Odorants/analysis , Volatile Organic Compounds/analysis
This study aims to investigate a flow cytometry performance-based methodology to detect anti-live (FC-ALPA-IgG) and anti-fixed (FC-AFPA-IgG) Leishmania (Viannia) braziliensis promastigote IgG as a means to monitor post-therapeutic cure of patients with localized cutaneous leishmaniasis (LCL). Serum samples from 30 LCL patients infected with L. (V.) braziliensis were assayed, comparing the IgG reactivity before and after specific treatment with pentavalent antimonial. Reactivities were reported as the percentage of positive fluorescent parasites (PPFP), using a PPFP of 60% as a cut-off value. In the serum dilution of 1:1024, the positive percentage of LCL serum sample for FC-ALPA-IgG and FC-AFPA-IgG was 86% and 90%, respectively, before treatment. Analysis of ∆PPFP that represents the difference between PPFP after and before treatment appeared as a new approach to monitor post-therapeutic IgG reactivity in LCL. Our data support the perspective of using FC-ALPA and FC-AFPA as a useful serologic tool for diagnosis and for post-therapeutic follow-up of LCL patients.
Antibodies, Protozoan/blood , Drug Monitoring/methods , Flow Cytometry/methods , Immunoglobulin G/blood , Leishmania braziliensis/immunology , Leishmaniasis, Cutaneous/diagnosis , Leishmaniasis, Cutaneous/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Antiprotozoal Agents/administration & dosage , Female , Humans , Leishmaniasis, Cutaneous/immunology , Male , Middle Aged , Treatment Outcome , Young Adult
