Detection of Changes in Total Antioxidant Capacity, the Content of Polyphenols, Caffeine, and Heavy Metals of Teas in Relation to Their Origin and Fermentation

Tea (Camellia sinensis) is widely sought for beverages worldwide. Heavy metals are often the main aims of the survey of teas, given that the use of agricultural fertilization is very frequent. Some of these may affect the content of bioactive compounds. Therefore, in this study, we analyzed fermented and non-fermented teas of a single plant origin from Japan, Nepal, Korea, and China, and described mutual correlations and changes in the total antioxidant capacity (TAC), and the content of polyphenols (TPC), caffeine, and heavy metals in tea leaves, in relation to the origin and fermentation process. Using UV-VIS spectrophotometry and HPLC-DAD, we determined variations in bioactive compounds’ content in relation to the fermentation process and origin and observed negative correlations between TAC and TPC. Heavy metal content followed this order: Mn > Fe > Cu > Zn > Ni > Cr > Pb > Co > Cd > Hg. Given the homogenous content of these elements in relation to fermentation, this paper also describes the possibility of using heavy metals as determinants of geographical origin. Linear Discriminant Analysis showed an accuracy of 75% for Ni, Co, Cd, Hg, and Pb, explaining 95.19% of the variability between geographical regions

Blackcurrant (Ribes nigrum L.) and Kamchatka Honeysuckle (Lonicera caerulea var. Kamtschatica) Extract Effects on Technological Properties, Sensory Quality, and Lipid Oxidation of Raw-Cooked Meat Product (Frankfurters)

Oxidation is one of the most prevalent factors responsible for meat product deterioration. Due to their potential health risks, commonly used synthetic antioxidants are beginning to be frowned upon by customers. The industry is searching for a natural replacement. In our study, we incorporated blackcurrant (Ribes nigrum L.) and Kamchatka honeysuckle (Lonicera caerulea var. Kamtschatica) extracts into raw-cooked meat products (frankfurters) as natural antioxidants. We observed that both extracts at concentrations of 3 mL·kg−1 were able to significantly (α = 0.05) postpone lipid oxidation in our samples, with results comparable to vitamin C (0.5 mg·kg−1) addition. Moreover, we did not observe negative effects of the extracts on the product’s color, pH, or textural properties. Negative results were reported in the sensory evaluation of honeysuckle addition samples. This could have been caused by the natural strong and bitter taste of honeysuckle, which was transferred to the extracts and, subsequently, into the meat product

Volatiles as chemical markers suitable for identification of the geographical origin of green Coffea arabica L

Traceability of geographical origin is a challenging matter for producers and consumers. This research focuses on identifying green Coffea arabica from Africa, South and Central America using volatiles and aqueous-soluble chemical compounds for the first time. Using Linear Discriminant Analysis, we created two models. The first one focused on aqueous soluble compounds and their properties (pH, total antioxidant capacity, total polyphenolic content, caffeine, and chlorogenic acids) showed 91.30% accuracy of identification and, during cross-validation, predicted 82.61% correct identification. The 83.36% of the variability was explained with caffeine and TAC. The second focused on volatiles correctly identifying 100% of testing samples and predicted 86.96% accuracy in cross-validation. 91.17% of the variability between African, South, and Central American coffees was explained based on ketones, aldehydes, organic acids and esters, nitriles, alcohols, and alkenes, while ketones appeared as the strongest parameter among volatiles.This research was supported by The Ministry of Education, Science, Research and Sport of the Slovak Republic, grant VEGA 1/0734/20 and Consejo Superior de Investigaciones Científicas (CSIC) (project 201970E117). Special thanks go to the European Institute of Innovation & Technology (EIT) and EIT Food RIS Fellowships.Peer reviewe

Comparative Analysis of Selected Chemical Parameters of Coffea arabica, from Cascara to Silverskin

Nowadays, there is an increased interest in coffee derivatives (green beans, roasted beans, and coffee by-products (Cascara and Silverskin)) due to their particular chemical composition. This study aimed to compare the content of dry matter, total fat, fatty acids, and fiber (ADF, NDF) of coffee by-products (Cascara and Silverskin) and coffee beans (green and roasted under different conditions). Coffee beans and their by-products were obtained from 100% C. arabica coffee cherries from Panama by dry process. The lowest concentrations of fat corresponded to Cascara 4.24 g·kg−1 and Silverskin 23.70 g·kg−1, respectively. The major fatty acids detected in all samples were palmitic, stearic, oleic, and linoleic acids, the latter two being essential fatty acids. LDA showed that 89.01% of the variability between beans and by-products was explained by lignoceric, myristic, behenic, tricosanoic, arachidic, and heneicosanoic acids. Silverskin appeared to be a good source of lignoceric, myristic, and behenic acids and had a higher concentration of dietary fiber (314.95 g·kg−1) than Cascara (160.03 g·kg−1). Coffee by-products (Silverskin and Cascara) are low-fat products enriched in dietary fiber. Their incorporation, after adjustment, into the global diet may contribute to nutrition security, the sustainability of the coffee sector, and human health