Content of flavan-3-ol monomers and gallic acid in grape seeds by variety and year

The content of flavan-3-ol monomers and gallic acid in grape seeds in the samples from the gene collection of Viticulture Research Station Karlštejn (Czech Republic) was investigated. Presence of catechin, epicatechin, epigallocatechin, epicatechin gallate and gallic acid was confirmed in these samples, other flavan-3-ol monomers like gallocatechin or epigallocatechin gallate were below limit of detection. As major flavan-3-ol monomers catechin and epicatechin with 85 % were detected. Average content of catechin in grape seed was 4454 ± 148 µg·g-1, 3085 ± 98 µg·g-1 epicatechin, 600 ± 41 µg·g-1 epigallocatechin, 457 ± 19 µg·g-1 gallic acid, and 352 ± 16 µg·g-1 epicatechin gallate. Variety had main impact on phenolic content followed by vintage. Average sum of flavan-3-ol monomers in grape seeds in white varietes was 7601 ± 273 µg·g-1 and 10869 ± 430 µg·g-1 in red varieties, with 10050 ± 425 µg·g-1 in 2012 and 7846 ± 219 µg·g-1 in 2013 were found on average in all varieties, respectively.  The highest phenolic content was characteristic for 'Pinot Noir', 'Muskat Donskoi', 'Aromriesling' and 'Hibernal' and may contribute to their health properties

Suppl. material for JIFF 23524588-20230016 - Does the addition of edible insects affect the formation of acrylamide during bread baking?

The effect of insect powder addition on the acrylamide formation in leavened and unleavened wheat bread and on the content of its main precursors in raw material was investigated. The samples under study were prepared form wholemeal wheat flour supplemented with 5, 8, and 12% of field cricket or yellow mealworm powder. The addition of both insects increased the content of reducing sugars and free amino acids, except for asparagine, the limiting factor of acrylamide formation in cereal products, which was lower in the samples with the greatest cricket and mealworm supplementation than in the control wheat flour (242.4 and 177.9 vs 249.6 mg/kg). For unleavened bread, an increase in acrylamide was recorded with the highest share of cricket and mealworm compared to the control (up to 14.03 and 29.52 vs 11.02 µg/kg). Conversely, for leavened bread, the variants most supplemented with cricket and mealworm exhibited the lowest acrylamide content relative to the control (64.84 and 68.78 vs 82.47 µg/kg). It is indicated by the results that the supplementation of bakery products with insects enriches their nutritional value and does not pose a risk of increased acrylamide intake by consumers. </p