Growth performance and nutritional profile of mealworms reared on corn stover, soybean meal, and distillers’ grains Abstract Mealworms are commercially reared on diets comprising of mixed grains. Substituting grains with agro-food industry by-products creates opportunities to valorize by-products and lowers the cost of insect rearing practices. In this study, three by-products (mushroom spent corn stover, highly denatured soybean meal, and spirit distillers’ grains) as treatments and wheat bran as control were used to rear mealworms. For growth performance, mealworms dry weights reared on three by-products were 53–67% of control. Feed conversion and utilization ratios ranged from 36 to 45% and 50 to 57% of control, respectively. For nutritional profile, protein and fat fractions ranged from 70 to 76% and 6 to 12% of mealworm dry weight, respectively. Leucine, lysine, methionine + cysteine, threonine, and valine were the limiting amino acids comparing with FAO/WHO requirements. The major fatty acids were linoleic acid (C18:2, 30–38%), oleic acid (C18:1, 24–34%), and palmitic acid (C16:0, 14–17%). The comparable nutritional profile demonstrated the potential to rear mealworms using these three cheap by-products. The results provide a reference for insect farmers to formulate the diets for obtaining specific insect products with desired nutrient composition.

Edible Rhus tripartita fruit as source of health-promoting compounds: characterization of bioactive components and antioxidant properties Abstract The fruits of Rhus tripartita had recently attracted great attention due to its notable therapeutic effects. Their potential effects are attributed to the richness of diverse classes of secondary metabolites. The objective of this research was to access the determination of chemical composition and antioxidant properties of R. tripartita fruit extracts and its partitioned fractions (absolute petroleum ether, 70% aqueous ethanol, absolute ethyl acetate and water). LC–ESI-MS/MS and FTIR–ATR were used to assess the potential of R. tripartita fruits as a source of health-promoting constituents. A total of 38 phenolics, including flavones, flavonols, flavanones, organic acids, hydroxycinnamic acids and hydroxybenzoic acids, 26 of them were reported for the first time in R. tripartita. The main compounds were apigenin7-O-glucoside, apigenin and p-coumaric acid. The FTIR–ATR analysis results revealed the presence of characteristic functional groups such as − OH, C–O, − C = C and C–H of phenolic compounds, carboxylic acids, carbohydrates, lipophilic components and proteins in R. tripartita fruits. Furthermore, the ethyl acetate fraction showed the highest level of phenolic contents and strong antioxidant activities. The present study recommends R. tripartita fruits as source of natural antioxidants which can be used as bioactive ingredient for functional foods and nutraceuticals.

Valorization of the agro-forestry wastes from Italian chestnut cultivars for the recovery of bioactive compounds Abstract Chestnut is a very promising forest species that may be used as biomass to recover high value-added biomolecules. Four cultivars coming from the Italian Park “Roccamonfina-Foce Garigliano” were characterized at biochemical level by phenolic chromatographic profiling and by means of antioxidant activity. The phenolic compounds were extracted from leaves, burs, and shells for all cultivars and the inner shells resulted the richest by-product in all varieties. Comparison of data sets using principal component analysis led to conclusions regarding the biochemical relationships among all cultivars. Furthermore, cluster analysis with HPLC data on the phytochemical compounds produced a dendrogram showing the relationships within Italian cultivars, so confirming the same pattern showed in PCA. In conclusion, high added-value bioactive compounds, utilized as dietary and pharmaceutical supplements, can be achieved from non-edible chestnut components discarded during post-harvest and food processing, so improving the valuable capacity of recycling of chestnut wastes.

Identification and in silico analysis of antithrombotic peptides from the enzymatic hydrolysates of Tenebrio molitor larvae Abstract Tenebrio molitor is an excellent source of high-quality protein that produces various bioactive peptides. It is a traditional Chinese herbal medicine which has the effect of “activating blood and dissolving stasis”. It aimed to obtain antithrombotic peptides from the Tenebrio molitor larvae hydrolysate generated by treatment with pepsin and trypsin. The hydrolysate was subjected to ion exchange chromatography and gel filtration chromatography; the obtained antithrombotic activity values of the fractions were 40.87% and 65.61% at 8.0 mg/mL, respectively. After further preparation by reverse-phase liquid chromatography, the peptides with antithrombotic activity of 28.66% at 0.2 mg/mL were identified by liquid chromatography tandem mass spectrometry as SLVDAIGMGP and AGFAGDDAPR. Both of the peptides were shown to be nontoxic and could interact with thrombin exosite 1 by molecular docking. These results indicate that peptides from Tenebrio molitor might be used as potential antithrombotic components in the future.

The role of hydrogen peroxide in the antibacterial activity of different floral honeys Abstract Because of its powerful therapeutic potential in wound care, honey has been given much attention. One of the most relevant and researched characteristics of honey is its multifactorial antibacterial activity. Several antibacterial compounds have been identified including hydrogen peroxide (H2O2). The goal of the study was to characterize the antibacterial potential of honeys from various botanical origins (n = 233) against Staphylococcus aureus and Pseudomonas aeruginosa and establish the H2O2 content. Five types of honey were identified: acacia (n = 72), linden (n = 23), rapeseed (n = 9), sunflower (n = 8) and multi-floral (n = 121). The overall antibacterial activity of all the honey samples, expressed as a minimal inhibitory concentration of honey, strongly correlated with the level of H2O2. On the other hand, linden honey, which exhibited the strongest antibacterial effect, showed weak or no correlation between the antibacterial activity and the level of H2O2, depending on bacterial strain. The weakest antibacterial activity was documented in the rapeseed honey samples and it was associated with the low content of H2O2. These data suggest that antibacterial activity of honey is mainly H2O2-dependent; however, certain type of honey such as linden honey, showed a strong antibacterial effect which, may be, at least partially, attributed to non-peroxide factor(s).

Fruit aroma and sensorial characteristics of traditional and innovative Japanese plum ( Prunus salicina Lindl.) cultivars grown in Italy Abstract Plums are climacteric fruits with reduced shelf life and they represent a very appreciated product for fresh consumption. European consumers can find several plum cultivars that offer different organoleptic characteristics, flavor and aroma. In this study, chemical properties, such as total soluble solids (TSS), pH, titratable acidity, total phenolic and anthocyanin contents, aroma profile and sensory evaluation of seven plum cultivars were investigated. Significant differences in chemical properties were found in ‘Settembrine’ and ‘Angeleno’, the late ripening European plums that showed the highest TSS content and the lowest acidity values. As expected, a high level of anthocyanins was detected in red pulp and red flesh plums such as ‘Dofi Giudy’ and ‘Black Diamond’, though significant differences in their total phenolic amount were observed. ‘Dofi Giudy’, ‘Black Diamond’ and ‘Laroda’ showed the highest aroma profile among the investigated cultivars. Finally, a discrimination among the cultivars was obtained by combining the volatile profiles with a back-propagation neural network analysis (BPNN). The results showed that C6 compounds such as esters and aldehydes were strongly related to flavor perception of the panelists. ‘Dofi Giudy’ was the mostly appreciated plum due to its juiciness, sweetness and flavor intensity; furthermore, when compared to the other cultivars, it also showed remarkable levels of total soluble solids, total phenolic and anthocyanin contents.

Using Torulaspora delbrueckii , Saccharomyces cerevisiae and Saccharomyces bayanus wine yeasts as starter cultures for fermentation and quality improvement of mead Abstract Wine yeast strains Torulaspora delbrueckii, Saccharomyces bayanus and an osmo-ethanol tolerant Saccharomyces cerevisiae strain isolated in a Pedro Ximenez grape must have been used as starter cultures for mead production without addition of nitrogen assimilable sources. Significant differences on the fermentation kinetics, major volatile compound (MVC) contents and in organoleptic properties (OP) were obtained. A Multivariate Analysis (MVA) carried out with the contents in the six key compounds, acetaldehyde, 1-propanol, isobutanol, acetoin, 2,3-butanediol (levo) and diethyl succinate, allows to obtain a chemical profile or fingerprint very useful to differentiate each mead. By subjecting these MVC to a principal component analysis, two PCs were obtained that explain the 85.3% of variance and group the meads according the yeast used. Meads obtained with T. delbrueckii have a low ethanol, high residual sugar content and preserve the primary aroma of honey. It was concluded from a sensorial evaluation that the most suitable yeast that produces the sweet type of multifloral honey mead is T. delbrueckii, while S. bayanus is suitable for dry meads.

Spray-dried Ancellotta red wine: natural colorant with potential for food applications Abstract Ancellotta red wine (Vitis vinifera L.) was encapsulated by spray-drying (inlet and outlet temperatures were 145 °C and 70 °C, respectively) to obtain a wine powder with a low water activity (aw) using maltodextrin DE10 as an encapsulating agent. The retention of total monomeric anthocyanins (TMA) in the wine powder was found to be greater than 80%. Anthocyanin profiles of Ancellotta liquid wine and wine powder were characterized by using HPLC–DAD and 33 compounds were identified. The wine powder was stored under two different water activity values (aw 0.25 and aw 0.33). Furthermore, the TMA (pH-differential method), total anthocyanins and malvidin-3-glucoside were determined by HPLC–DAD for up to 90 days’ storage at 38 °C. Total anthocyanins and malvidin-3-glucoside decreased very slowly during storage. The stability of anthocyanins and color differences (ΔE*ab) in 1% wine powder solution at different pHs and temperatures were evaluated. These results indicated that Ancellotta wine powder has the potential to be used as a food colorant in low pH and low water activity foods.

Cross-flow filtration of lees grape juice for non-aromatic white wine production: a case study on an Italian PDO Abstract During white winemaking, after clarification, a considerable amount of juice remains trapped in the lees. Recently, cross-flow filtration has become popular to recover a large amount of juice from lees. However, high juice recovery is observed to be consistent with a decrease in wine quality, while low recovery reduces the amount of wine that can be produced. Therefore, this study aims to find the optimal compromise between quantity and quality. We tested at industrial scale and in three replicates, qualitative changes in an elite Italian white wine as a function of different amounts of juice recovered. The length of the filtration cycle affected the juice’s chemical parameters. In some cases, uncontrolled alcoholic fermentation started before the yeast inoculum, leading to a small increase in ethanol, and higher acetic acid and ethyl acetate concentrations that can be find in the resulting wines. The phenomenon was particularly apparent in longer fermentation cycles. Furthermore, longer filtration cycles increased juice acidity and potassium, while the resulting wines changed in terms of pH, glycerol, and volatile profile. Several grape-related compounds were found in wines at different concentrations as a function of the amount of juice recovered. In particular, Z3-hexen-1-ol, p-cymene, β-ionone, and benzyl alcohol were found to increase, reaching a maximum at 65% of recovered juice before decreasing. Furthermore, several fermentation-related compounds were found to change according to the length of the filtration cycle. Our work identifies an optimal recovery point of 65%. This percentage appears the best trade-off between the flavor of wines, fermentation risk management, and the amount of juice recovered.

Substances in beer that cause fluorescence: evaluating the qualitative and quantitative determination of these ingredients Abstract Fluorochromes can impair analysis results or, due to their natural frequency (molecular vibrations) completely superimpose important signals and make measurements impossible. This is especially true for non-invasive, optical measuring methods such as Raman microspectroscopy, which reach their limits when fluorochromes are present. Beer contains many fluorescent substances, e.g., amino acids, vitamins and phenolic compounds. Therefore, in this study, eight different beers (lager beer, dark lager, Pilsner beer, Radler beer, wheat beer, dark wheat beer, alcohol-free lager beer, and alcohol-free wheat beer) were examined for their fluorescent ingredients. Using the PARAFAC model, the fluorescence of the eight beers could be explained for three components. By comparing with existing database literature, these components could be qualitatively assigned to the organic substances DOM (dissolved organic matter), DOC (dissolved organic carbon) or CDOM (colored dissolved organic matter) and OC (organic matter). The emission and extinction spectra helped to establish these organic substances as the three aromatic amino acids phenylalanine, tryptophan and tyrosine, iso-α-acid, phenolic compounds and the vitamin B group. In addition, correlations with the fluorescence intensities from the EEM (excitation–emission matrix) data were detected in combination with beer analyses. A correlation between the fluorescence intensity of origin and iso-α-acid could therefore be shown. The fluorescent amino acids phenylalanine, tryptophan and tyrosine showed only slight correlations with the fluorescent intensity. The calculated data showed that fluorescence spectroscopy with the obtained EEM represents a powerful real-time measurement, which offers sensitive monitoring for the identification of fluorescent substances in beer samples. Qualitative analysis combined with the PARAFAC analysis is also advantageous to identify the main components.