Evaluation of physicochemical, sensory, and antimicrobial properties of small-scale produced fruit vinegars

Hungarian fruit vinegars were characterised in terms of physicochemical attributes (total polyphenol content, antioxidant characteristics/FRAP, CUPRAC, ABTS/, ascorbic acid content, pH, total soluble solids), sensory profiles, and antimicrobial properties. Both compositional and sensory profiles showed distinct patterns depending on the type of vinegar (Tokaj wine, balsamic or apple) and the additional fruit used. Balsamic vinegars maturated on rosehip, sea buckthorn, and raspberry showed outstanding antioxidant performances. Rosehip, raspberry, and quince vinegars, as well as vinegars produced from Tokaji aszú and balsamic apple obtained high scores for fruity and sweet notes. Antimicrobial activities were tested on Gram-negative and Gram-positive organisms, including probiotic bacteria. Generally, only weak activities were obtained, which was attributed to the natural sugar content of the samples, depending on the type of the vinegar and the fruit. Similar results, but more pronounced bacterial growth inhibitions were obtained for probiotic strains, however, some probiotic strains were resistant to at least two of the vinegars. Based on these, balsamic apple, raspberry, rosehip, quince, and sea buckthorn may qualify as potential functional components of probiotic preparations containing some of the strains tested.

Different values obtained by the FRAP method for the determination of slowly and rapidly reacting phenols

A number of methods have been applied to measure total antioxidant capacity (TAC), including FRAP, which is based on reducing the amount of iron ions in a complex compound. Researchers often use measurement of absorbance 10 min after mixing a sample with the FRAP reaction solution to calculate TAC. The FRAP solution has been shown to alter absorbance over time by ca 0.0010–0.0020 per hour, under storage conditions. This article intends to show that some substances do not fully or sufficiently react within the common analysis period. It is evident from the results that some substances react more quickly and others very slowly. Absorbance in relation to various phenols was measured. Compared to the levels of absorbance at 10 min, mean absorbance at 48 h was higher by 5,395% for vanillin, 426% for caffeic acid, 170% for sinapinic acid, 67% for gallic acid, 19% for syringic acid, and only by 4% for Trolox. Results for vanillin and caffeic acid indicate potential auto-catalysis.

Isolation and identification of peptides from Pinctada martensii with osteogenic activity

Marine organisms have attracted considerable attention in recent years. In this study, peptides with osteogenic activity from Pinctada martensii were isolated and identified. Additionally, the effects of the hydrolysates on MC3T3-E1 cell proliferation and differentiation were evaluated using the MTT and alkaline phosphatase (ALP) assays, respectively. First, trypsin, pancreatin, and neutral protease were used to hydrolyse the intact shellfish. The hydrolysates with the greatest effects on osteoblast proliferation and ALP activity were separated and purified. Second, fraction WP2 was isolated and purified using a Sephadex G-25 column. WP2, which had the highest osteogenic activity, increased cell growth by 48.57 ± 0.05% and ALP activity by 6.27 ± 0.07 mU. Finally, four novel peptides were identified in WP2 (FDNEGKGKLPEEY, IVLDSGDGVTH, IVLDSGDGVSH, and SSENSDLQRQ) by Orbitrap Fusion Lumos Tribrid orbital liquid chromatography-mass spectrometry. Our findings revealed that P. martensii contains peptides with potential osteogenic activity.

Tasting experiences on local apple cultivars with blind and sighted consumers

Consumers increasingly address their attention to healthy fruits produced under organic agricultural managements. However, such produce may be less appealing in appearance influencing the purchase decisions of consumers. This research had the purpose to determine on three Italian local apple cultivars (Casciana, Rosa, Ruggine) the sensory appreciation of fruit through experiments conducted with blind (BC) and sighted (SC) consumers. The appreciation of apples differed between consumers with different visual ability. This aspect mainly concerned cvs Casciana and Rosa with contrasting fruit appearance traits. The BCs were inclined to better evaluate Casciana apples characterised by less attractive fruits. Conversely, the visual factor could have influenced the SCs’ judgment, as they appreciated Rosa more by the best outer traits of fruits. Intriguing responses were obtained when SCs were blindfolded.

Medium chain fatty acids and fatty acid esters as potential markers of alcoholic fermentation of white wines

Aroma components of wines play an important role in the sensory quality of wines. In our paper we investigate the effect of commercially available yeast nutrients under different fermentation parameters. Caproic acid, caprylic acid, capric acid, and different fatty acid esters were used as markers of the alcoholic fermentation process. The optimal temperature for the fermentation of different white wines was at 15–16 °C, in the case of examined wines lower concentrations of fatty acids and fatty acid esters were found at this temperature. At 25–26 °C fermentation temperature very high concentrations of fatty acids and fatty acid esters were detected. Applying different nitrogen-containing wine additives we managed to achieve better aroma profiles for white wines even using musts of lower quality.

Biodiversity of Zygosaccharomyces species in food systems

Abstracts Zygosaccharomyces species are among the most problematic food spoilage yeasts. The two most infamous species are Zygosaccharomyces balii and Zygosaccharomyces rouxii, although they may also take a positive role during the production of some fermented foods. DNA sequence based yeast identification aided by freely available reference databases of barcoding DNA sequences has boosted the description rate of novel yeast species in the last two decades. The genus Zygosaccharomyces has been considerably expanded as well. Especially the number of the extremely osmotolerant Zygosaccharomyces species, related to Z. rouxii and regularly found in high-sugar foods, has enlarged. A brief account of recent developments in the taxonomy and biodiversity of this important food associated genus is given in this review.

The ratio of xylooligosaccharide to ferulic acid affects faecal ferulic acid content, short chain fatty acid output, and gut stress

There have been contradicting observations regarding the prebiotic efficacy of feruloylated oligosaccharides (FOs) extracted from different varieties of cereals with varying oligosaccharides and ferulic acid (FA) levels. The present study was performed to determine whether the mass ratio of xylooligosaccharide (XOS) to FA influences their combined effects on faecal FA content, short chain fatty acid (SCFA) output, and gut stress of d-galactose-treated aging rats. The results show that there was no significant difference in the faecal FA levels of rats fed with 5:1 and 10:1 XOS:FA diet, although the FA level in the 5:1-supplemented diet was twice as much as in the 10:1 diet. More utilisation of FA decreased butyric acid and SCFA output in the faeces for diet 5:1 compared with diets 10:1 XOS:FA or XOS alone. Furthermore, compared with 10:1 XOS:FA or XOS alone treatments, the 5:1 XOS:FA diet resulted in increased 1-diphenyl-2-picrylhydrazyl activity and higher ratios of Bifidobacterium or Lactobacillus to Escherichia coli (P < 0.05), while not increasing the number of probiotic Bifidobacterium and Lactobacillus. These findings suggest that under the specific stress level set for this study, the sufficient amount of FA added to XOS (5:1) can stimulate FA utilisation to modify gut redox balance, while reducing faecal SCFA output.

Effects of shorts, by-product of milling, on the chemical composition and quality properties of pasta

The aim of this study was to investigate the effects of wheat shorts, a milling by-product, on some properties of pasta. For this purpose, wheat semolina was replaced with wheat shorts at 15, 30, and 45% levels in pasta formulation. Some physical, chemical, and sensory properties of pasta samples were evaluated and compared with control samples prepared with durum wheat semolina. As the concentrations of shorts increased in the pasta formulation, the brightness values decreased and the redness values increased. The ash, fat, total dietary fibre, total phenolic content, antioxidant activity, and mineral content increased with the use of shorts. The highest solid loss value (10.28%) was found in pasta samples containing 45% shorts. The addition of shorts up to 30% presented similar overall acceptability scores to control pasta samples. As a result, it was observed that as the shorts content of the samples increase, the nutritional value and the levels of some components that affect health positively, increase as well. So, the samples containing 30% shorts appear to be at forefront due to health effects and overall acceptability scores.

Investigation of probiotic potential of yeasts isolated from sourdoughs from different regions of Turkey

In this study, 14 yeast cultures from 62 isolates from traditional sourdoughs collected from 6 different regions of Turkey were selected by FT-IR identification and characterised to reveal their probiotic properties. Four yeast strains were genotypically identified and compared with FT-IR identification. In all analyses, it was observed that mostly Saccaromyces cerevisiae strain exhibited high hydrophobicity, auto-aggregation feature, and all yeast isolates in this study showed tolerance to 0.3%, even salt concentration. In addition, all yeast strains were susceptible to anti-yeasts agents, although they were resistant to all antibiotics used in the study. All selected yeast isolates exhibited high antimicrobial activity against the Staphylococcus aureus. In conclusion, this study investigated the potential probiotic properties of yeast strains isolated from sourdough.

Selection of Calabrian strains of Saccharomyces sensu stricto for red wines

Phenolic compounds provide important quality attributes to red wines interacting with the organoleptic impact of wines. Yeast mannoproteins can interact with grape phenolic compounds, responsible for colour and antioxidant activity of wines. The aim of this work was to perform oenological characterisation and specific selection of Calabrian strains of Saccharomyces sensu stricto. Among the considered traits, the aptitude of the yeast to preserve grape pigments and colour intensity was included. Among the best six yeast strains – Sc2731, Sc2742, Sc2756, Sc2773, Sc2774, and Sc2823 – strain Sc2742 exhibits the highest Folin–Ciocalteu index and strain Sc2774 the highest colour intensity. These two selected yeasts may be used as starter for the production of red wines in order to preserve grape pigments and colour intensity.