Filters
Relationships Between Photosynthetic Efficiency and Grain Antioxidant Content of Barley Genotypes Under Increasing Nitrogen Rates
Nitrogen fertilization may affect the functioning of photosynthesis as well as the chemical composition and antioxidant potential of cereal grains. Little is known about the relationship between the efficiency of photosynthesis and the content of phenolic compounds in barley grain, especially in conditions of varying nitrogen availability. In this regard, a field experiment was conducted to examine the responses of two primary barley genotypes with elevated phenolic compound content (TPC) in grain and an intensive modern cultivar H. v. vulgare with high protein content to increasing nitrogen fertilization (rates of 0, 30, 60 and 90 kg N ha−1) during the study years, which differed in terms of hydrothermal conditions. The leaf greenness index (SPAD) and chlorophyll fluorescence parameters were evaluated on three occasions throughout the growing season. Following the harvest, the chemical composition of the grains, including phenolic acids, flavonoids and antioxidant potential, was evaluated. The antioxidant potential and chemical composition of the grain, including TPC and protein content, depended to the greatest extent on genetic and environmental factors, and only then on nitrogen fertilization. Nitrogen increased the TPC content and antioxidant capacity ABTS+ of the grains of all studied genotypes and the protein content in H. v. vulgare grain. Rates of 60 and 90 kg N ha−1 resulted in a significant increase in the SPAD, PIabs and Fv/Fm in BBCH 34 and 57. A positive correlation was confirmed between the SPAD and PIabs and the content of TPC and ABTS+ in the grain. The dependence of qualitative characteristics on the Fv/Fm was also demonstrated. The primary genotypes are characterized by a greater genetic potential for the synthesis of phenolic compounds than the modern cultivar H. v. vulgare. The synthesis of phenolic compounds, and thus their accumulation in the grain, is clearly stimulated by unfavorable environmental factors and moderate nitrogen rates and depends on the chlorophyll content in the leaves and the efficiency of photosynthesis. N fertilization has a beneficial effect on the content of phenolic compounds in grain resulting from the improvement in the SPAD and PIabs. The chemical composition of grain and the increase in antioxidant potential are determined by the Fv/Fm, which is low under hydrothermal stress conditions.
Application of Chia and Flaxseed Meal as an Ingredient of Fermented Vegetable-Based Spreads to Design Their Nutritional Composition and Sensory Quality
Fermented vegetable spreads could offer an opportunity to diversify the range of plant-based foods. The challenge in developing the spreads is to achieve high quality, including stable consistency, consumer desirability and high nutritional value. The aim was to evaluate the application of chia and flaxseed meal for fermented zucchini-cucumber spread production. The effect on the chemical composition, phenolic compound content, antioxidant activity, and sensory quality of the vegetable spread was evaluated. Its color, viscosity, and microstructure were also analyzed using instrumental methods. The meal addition varied from 4.0 to 14.0%. The spread with meal addition had higher fat, protein, ash, and dietary fiber content than the control. Total free phenolic compound content and antioxidant activity also increased, and chia seed meal impacted the parameters more. On the contrary, flaxseed meal improved more the product’s consumer desirability than chia. Both were effective gelling agents that increased viscosity and enhanced product spreadability, and only flaxseed meal showed a masking ability. Its addition reduced the perception and intensity of the bitter, tart, and sour taste. The spread formula consisting of fermented zucchini and cucumber with 9 to 11.5% flaxseed meal addition was the most recommended to achieve the product with high consumer desirability.
The Application of Mulberry Elements into a Novel Form of Easy-to-Prepare Dried Smoothie
The European market offers a variety of functional foods targeted at prediabetic and diabetic patients, with different approaches to reducing postprandial glucose levels. The utilization of white and black mulberry in new products could be an area of interest to many conscious consumers. The study aimed to design a novel form (dried) of easy-to-prepare product by applying nutritious mulberry in various proportions and creating an aesthetically appealing smoothie product with a distinctive taste profile. Such an easy-to-prepare form of smoothie was obtained by utilizing the freeze-drying process, while typical market smoothies are liquid. Sensory evaluations of the fresh, dried, and reconstructed smoothies and their basic characteristics were conducted. Moreover, antiradical tests (with ABTS+• and DPPH•), the phenolic compound profile (HPLC/PDA), and the L*a*b profile were analyzed. The results of the sensory evaluation tests were divided into two groups: Polish and foreign panelists. It was observed that mulberry-licorice drop-based smoothies were preferred fresh. Yet dried and reconstituted capsule-based smoothies were favored overall. Generally, both Polish and foreign panelists preferred lower concentrations of mulberry and licorice extracts (DB) in fresh smoothies, while in dried or reconstructed smoothie form, panelists scored higher (DC) and lower (DB) concentrations quite similarly (favored both concentrations). From the group of identified phenolic compounds, cinnamic acid derivates dominated all analyzed smoothies. Many analyzed types of flavonoids (quercetin, rutin, kaempferol) and naringenin were found in the smoothies. Some differences were noted in the antiradical tests but were only statistically significant for DPPH• scavenging activity, which was higher for the DB1, DB2, and DC1 samples. Generally, even higher addition of licorice and mulberry did not negatively affect panelists’ ratings and the analyzed activities.
The Effect of Ultrasound and Lactic Acid Fermentation on the Selected Quality Parameters and Bioactive Compounds Content in Fermented Pumpkin (Cucurbita pepo L.)
Increasing the consumption of fruit and vegetables can be achieved by creating new products. A promising method seems to be the directed fermentation of vegetables. The aim of this study was to investigate the effect of ultrasonic pretreatment (US; 25 kHz; 5 min) and the lactic acid bacteria strain (LAB; Lactiplantibacillus plantarum 299v and Lacticaseibacillus rhamnosus GG) on the quality of fermented pumpkin (Cucurbita pepo L.). The pumpkin was inoculated with 5 log CFU/g of specific LAB strain. Fermentation was carried out for 7 days at 35 °C. Some samples were US treated at the washing stage. During fermentation, there was an increase in the LAB count of 3 logarithmic cycles compared to the initial inoculum. For L. rhamnosus, preceding fermentation by US treatment contributed to an increased bacteria count of 4 logarithmic cycles. In the case of fermentation with L. rhamnosus, the lactic acid content was significantly higher than for L. plantarum. These samples are also characterized by higher sensory properties, desirability of taste, and overall desirability. Fermentation contributed to a decrease in carotenoid and phenolic compounds content and an increase in the antioxidant capacity of the pumpkins, regardless of the bacterial strain.