Muhamad Alfiyan Zubaidi

This study investigates the effects of four enzymatic treatments on the yield, physicochemical properties, and bioactive compounds of grape juices from two red (Golubok, Regent) and two white (Muscaris, Aurora) hybrid grape varieties. A total of 20 samples were prepared using four commercial enzyme formulations (Pectinex Ultra, Safizym Clear Plus, Safizym Press, and Rapidase color) applied at a concentration of 0.02% (w/w). The juices were evaluated for yield, total phenolic content, antioxidant capacities (ABTS, DPPH, FRAP), titratable acidity, turbidity, total soluble solids, and phenolic profile. The addition of enzymes significantly improved juice yield by 10% to 20%, with the effect varying depending on the type of enzyme and the variety of grapes. Pectinex Ultra was the most effective enzyme in reducing turbidity, while enzyme treatments had minimal impact on Brix levels and sugar concentration, which were primarily determined by the characteristics of each grape variety. The enzyme addition showed a minor influence on the titratable acidity of the juices, with slight increases observed in Muscaris, but the grape variety played a major role in determining the titratable acidity levels. Color parameters revealed that white grape juices (Muscaris and Aurora) were brighter than red varieties (Golubok and Regent). Additionally, enzyme treatments influenced the color, enhancing the red hues in red grape juices. Enzyme treatments also improved the antioxidant capacity of grape juices, especially in Aurora and Muscaris, although the effect on polyphenol content was more dependent on the variety of grapes, with red varieties showing higher levels of polyphenols than white varieties. These findings highlight the significant role of both enzyme treatments and grape variety in determining the quality and health-promoting properties of grape juice.

Elderflowers are used for both culinary and health purposes. Their composition and, therefore, their properties depend on the variety from which they were obtained. The aim of this study was to compare six cultivated varieties with the wild form. The research included determining the basic chemical composition, bioactive ingredients and antioxidant activity. This research confirms that elderberry flowers are rich in bioactive ingredients. The wild form turned out to be the most rich in bioactive ingredients, while among the tested varieties it was ‘Weihenstephan’; both of these forms were characterized by a high content of polyphenols (394.36 and 377.75 mg/100 g dm, respectively) and antioxidant activity. The PCA analysis showed general differences in the chemical composition of elderberry flowers, depending on the variety, in relation to 23 variables, as well as showing their mutual correlations and the strength of their influence on the PCA model.

The purpose of this article is to present information about changes in physical properties (pH, TA, and color) and chemical components with bioactive activity in cold brew coffee beverages, during storage before and after HTST processing. Coffee samples were tested using industrial technology (12,000 bottles per batch). The antioxidant activity of the samples was analyzed using ABTS and FRAP methods, the concentration of polyphenols was determined using the UPLC-MS chromatography coupled with mass spectrometry method, and microbiological tests were performed according to PN-ISO/PN-EN ISO standards. The pH value decreased during coffee storage, and the color changed significantly in brightness. Polyphenol concentrations were calculated in the range of 1800 to almost 3400 mg/L, and the antioxidant capacity for ABTS and FRAP reached the ranges of the results successively: 123–195 µMol/100 mL and 158–212 µMol/100 mL. It was observed that HTST pasteurization has a beneficial effect on preserving the beverage in microbiological terms. Also, a positive effect of the process on the release of chemical components responsible for bioactive properties from the beverage was observed, followed by a reduction in antioxidant activity during the first 90 days of storage and between 180 and 270 days during storage.

In this study, five varieties of hybrid grapes were processed into juice to assess the influence of variety, destemming process and enzyme addition on juice quality, including yield, physicochemical properties and bioactive compounds. The results highlighted that while the processing methods had some impact on juice quality, the inherent grape variety remained the most significant factor. Although similar treatments were applied to all varieties, there were differences in the quality attributes of the juice. In general, red grape juice had a higher polyphenol content and antioxidant capacity than white grape juice. Four phenolic acids, eleven flavonols, five flavan-3-ols and five anthocyanins were identified. While the polyphenolic profile of each sample depended on the treatment and the variety, regardless of the variety, destemming was found to increase the yield by around 10–15%, while the addition of enzyme improved the yield by around 20–30%. Although the addition of enzymes led to a higher polyphenol content, it changed the color profile of the juice as a result of the pigment’s skin extraction. In contrast, the destemming process did not influence the color of the juice, but at the same time, it reduced the health benefits due to the removal of potential bioactive compounds from the stems.

Viticulture in a cool climate is more challenging than in traditional wine regions. Due to the weather conditions, the berries may not achieve their full maturation composition. Therefore, suitable grape cultivars should be selected for cultivation in cool climate regions. The aim of this research was to compare selected grape cultivars grown under the same climatic conditions in terms of their antioxidant activity, chemical composition, and macronutrient contents. Their dry matter content, total soluble solids, pH, total acidity, and vitamin C were also analyzed. This research confirmed the existence of differences between the cultivars regarding their antioxidant activity, total soluble solids and polyphenols, and content of vitamin C and macronutrients.

Boletus edulis (King bolete) is one of the most consumed wild mushrooms on a global scale, but this is particularly the case in Poland. Several studies have reported that mushrooms accumulate many potentially toxic elements (PTEs) such as Hg, Pb, and Cd, which may lead to adverse effects. Therefore, in this preliminary study, an assessment of the potential of a microbial assay for risk assessment (MARA) for ecotoxicological testing of both dried samples of fruiting bodies of King bolete collected from several sites of Poland and water extracts of mushrooms being tested were analyzed. An evaluation of MARA response in Boletus edulis extracts was performed to identify their toxicity and then, using the same samples, instrumental determination of 10 elements (Al, As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, and Zn) was performed. In general, the MARA responses indicated that the samples were only slightly toxic or nontoxic. Similarly, most of the PTEs were not detected in all dried samples of the fruiting bodies of King bolete. However, the analysis of digested samples (total content) proved that the elements’ content in water extracts was markedly lower than in dried fruit bodies. It implies that the MARA test corresponded better to the elements that are well extracted in water. Therefore, the MARA system can be applied for toxic identification if the targeted toxin is highly extracted in water. Further and more detailed research is still needed to develop reliable approach in order to evaluate the ecotoxicity in food-related bio-based raw materials using the MARA assay.