An in-depth multiphasic analysis of the chocolate production chain, from bean to bar, demonstrates the superiority of Saccharomyces cerevisiae over Hanseniaspora opuntiae as functional starter culture during cocoa fermentation.

Hanseniaspora opuntiae is a commonly found yeast species in naturally fermenting cocoa pulp-bean mass, which needed in-depth investigation. The present study aimed at examining effects of the cocoa isolate H. opuntiae IMDO 040108 as part of three different starter culture mixtures compared with spontaneous fermentation, regarding microbial community, substrate consumption, and metabolite production dynamics, including volatile organic compound (VOC) and phytochemical compositions, as well as compositions of the cocoa beans after fermentation, cocoa liquors, and chocolates. The inoculated H. opuntiae strain was unable to prevail over background yeasts present in the fermenting cocoa pulp-bean mass. It led to under-fermented cocoa beans after four days of fermentation, which was however reflected in higher levels of polyphenols. Cocoa fermentation processes inoculated with a Saccharomyces cerevisiae strain enhanced flavour production during the fermentation and drying steps, which was reflected in richer and more reproducible aroma profiles of the cocoa liquors and chocolates. Sensory analysis of the cocoa liquors and chocolates further demonstrated that S. cerevisiae led to more acidic notes compared to spontaneous fermentation, as a result of an advanced fermentation degree. Finally, different VOC profiles were found in the cocoa beans throughout the whole chocolate production chain, depending on the fermentation process.

Genomic features, aroma profiles, and probiotic potential of the Debaryomyces hansenii species complex strains isolated from Korean soybean fermented food.

Fermented soybean products are gaining attention in the food industry owing to their nutritive value and health benefits. In this study, we performed genomic analysis and physiological characterization of two Debaryomyces spp. yeast isolates obtained from a Korean traditional fermented soy sauce "ganjang". Both Debaryomyces hansenii ganjang isolates KD2 and C11 showed halotolerance to concentrations of up to 15% NaCl and improved growth in the presence of salt. Ploidy and whole-genome sequencing analyses indicated that the KD2 genome is haploid, whereas the C11 genome is heterozygous diploid with two distinctive subgenomes. Interestingly, phylogenetic analysis using intron sequences indicated that the C11 strain was generated via hybridization between D. hansenii and D. tyrocola ancestor strains. The D. hansenii KD2 and D. hansenii-hybrid C11 produced various volatile flavor compounds associated with butter, caramel, cheese, and fruits, and showed high bioconversion activity from ferulic acid to 4-vinylguaiacol, a characteristic flavor compound of soybean products. Both KD2 and C11 exhibited viability in the presence of bile salts and at low pH and showed immunomodulatory activity to induce high levels of the anti-inflammatory cytokine IL-10. The safety of the yeast isolates was confirmed by analyzing virulence and acute oral toxicity. Together, the D. hansenii ganjang isolates possess physiological properties beneficial for improving the flavor and nutritional value of fermented products.

Dyeing of bacterial cellulose films using plant-based natural dyes.

The aim of this work was to test the use of plant-based natural dyes on bacterial cellulose (BC) to add aesthetic value to dyed pellicles while maintaining the mechanical properties. Natural pigments from Clitoria ternatea L. and Hibiscus rosa-sinensis were tested. The commercial ARAQCEL RL 500 was also used for comparison purposes. The behavior of biocellulose regarding dye fixation, rehydration, tensile strength, and elasticity was evaluated in comparison to the dried biomaterial, showing that dyeing is a process that can be performed on hydrated BC. Dyeing the BC films through an innovative process maintained the crystallinity, thermal stability and mechanical strength of the BC and confirmed the compatibility of the membrane with the dyes tested, from the observed Scanning Electron Microscopy (SEM) morphology of nanofibers. Dyed biomaterial can be applied to various products, as confirmed by the results of the mechanical tests. As environmental awareness and public concern regarding pollution increase, the combination of natural dyes and BC pellicles can produce an attractive new material for the textile industry.

Medicinal Plants from the Ouaddaï Province (Chad): An Ethnobotanical Survey of Plants Used in Traditional Medicine.

BACKGROUND/OBJECTIVE: Plants are the basis of all health care systems. This study sought to inventory the most used medicinal plants in the local therapeutic patrimony of the Ouaddaï (East Chad) through an ethnobotanical investigation. METHODS: The inventory described the plant parts used, their mode of preparation, and their therapeutic uses. RESULTS: Thirty-eight plants species are used for different purposes and diseases. The most used species belongs to the Mimosaceae (eight species), Caesalpiniaceae (four species), and Combretaceae (four species) families. The traditional medicinal uses, as well as the preparations, of these plants are diverse. The used parts are leaves (36.4%), peels (23.7%), fruits (18.2%), roots (10.9%), stems (5.5%), and other (5.3%). These plants are used to treat 16 different illnesses, notably amoebiasis (26.8%), respiratory infections (14.3%), fever (12.5%), kidney stones (7.1%), snake bites (7.1%), tooth decay (5.4%), and leprosy (5.4%). CONCLUSION: The results obtained from this survey constitute the starting point of an inventory of local medicinal plants to be completed by phytochemical, pharmacologic, and toxicologic studies to allow good exploitation of the local medicinal flora.

Hanseniaspora opuntiae, Saccharomyces cerevisiae, Lactobacillus fermentum, and Acetobacter pasteurianus predominate during well-performed Malaysian cocoa bean box fermentations, underlining the importance of these microbial species for a successful cocoa bean fermentation process.

Two spontaneous Malaysian cocoa bean box fermentations (one farm, two plantation plots) were investigated. Physical parameters, microbial community dynamics, yeast and bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the respective fermented dry cocoa beans. Similar microbial growth and metabolite profiles were obtained for the two fermentations. Low concentrations of citric acid were found in the fresh pulp, revealing low acidity of the raw material. The main end-products of the catabolism of the pulp substrates glucose, fructose, and citric acid by yeasts, LAB, and AAB were ethanol, lactic acid, acetic acid, and/or mannitol. Hanseniaspora opuntiae, Lactobacillus fermentum, and Acetobacter pasteurianus were the prevalent species of the two fermentations. Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus pentosus, and Acetobacter ghanensis were also found during the mid-phase of the fermentation processes. Leuconostoc pseudomesenteroides and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Tatumella saanichensis and Enterobacter sp. were present in the beginning of the fermentations and they could be responsible for the degradation of citric acid and/or the production of gluconic acid and lactic acid, respectively. The presence of facultative heterofermentative LAB during the fermentations caused a high production of lactic acid. Finally, as these fermentations were carried out with high-quality raw material and were characterised by a restricted microbial species diversity, resulting in successfully fermented dry cocoa beans and good chocolates produced thereof, it is likely that the prevailing species H. opuntiae, S. cerevisiae, Lb. fermentum, and A. pasteurianus were responsible for it.

Skin manifestations and immunological parameters in childhood food allergy.

According to Hansen's contact rule, the digestive system should be considered as the main shock organ, yet in food allergy, this is not the case. Very often specific food triggers clinical manifestations not involving the digestive system; that is, reactions are manifested either in the respiratory system, as asthma or rhinitis, or in the skin. In these cases the BALT (broncho-alveolar lymphoid tissue) and GALT (gastrointestinal lymphoid tissue) units play a basic role in the sensitizations. The purpose of this study was to determine the most frequent skin manifestations of food allergy among children, and the most frequently involved foods. We also thought it interesting to evaluate the diagnostic reliability of the different standard immunological parameters utilized by the study team in food allergy. All patients underwent intracutaneous tests with 12 groups of the most frequent food allergens, as well as serum IgE, antigen-specific IgE against foods, and antigen-specific histamine release tests. Antigen-specific IgG4 determination was performed in some cases. The results obtained confirmed previous studies, the most common manifestations being: angioedema (48%), followed by urticaria (31%) and atopic dermatitis (21%). Regarding the frequency of sensitization to different food allergens, in mono- or polisensitization, fish and egg stand out in our environment. Certain food allergens are more frequently responsible for specific skin manifestations. Thus, for fish sensitization, the most frequent skin manifestation is atopic dermatitis (50%); for egg sensitization, angioedema is the most frequent skin manifestation (50%); and for milk, urticaria (50%). Finally, and in agreement with previous works regarding the diagnostic reliability of in vitro techniques, we found that the histamine release test offered the highest percentage of diagnostic reliability. Only for sensitization to milk proteins did antigen-specific IgE demonstrate higher reliability. Once again, we stress that our main problem is the lower reliability of skin tests against food allergens than against inhalant allergens. We emphasize the importance of food as a major factor in the etiopathogenesis of atopic dermatitis, as well as the need to complement the study, when possible, by means of the in vitro techniques described.

Mung bean nuclease cleaves preferentially at the boundaries of variant surface glycoprotein gene transpositions in trypanosome DNA.

Telomere-linked genes coding for the variant surface glycoproteins (VSGs) of African trypanosomes have been difficult to clone because their flanking regions frequently lack restriction sites. Therefore, we constructed a genomic DNA library of fragments generated by digestion of purified trypanosome DNA with mung bean nuclease, an enzyme that cleaves before and after genes in Plasmodium falciparum DNA (McCutchan, T. F., Hansen, J. L., Dame, J. B., and Mullins, J. A. (1984) Science 225, 625-628). Southern hybridizations with several gene probes showed that under the appropriate conditions mung bean nuclease produces discrete trypanosome DNA fragments that are as clearly resolved on an agarose gel as restriction fragments. The majority of VSG genes are on fragments of about 1.7 kilobase pairs. To examine the sites of mung bean nuclease cleavage, the insert boundary sequences of eight recombinant clones in the library containing VSG genes were determined. In general, mung bean nuclease cleaved 300-800 base pairs in front of the VSG start codon and within 50 base pairs on either side of the termination codon. These regions also form the boundaries of VSG gene conversion events indicating that the enzyme recognizes, in part, a conformational structure rather than a specific sequence. The analyzed clones included both telomere-linked and interior basic copy VSG genes indicating that the library potentially contains all of the telomere-linked VSG genes in the genome.