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Maintaining a diverse diet is essential for the preservation of one's health and may contribute to the fight against significant civilization diseases such as obesity or diabetes. Sweet potato can be fitted into a diverse diet and serve as a functional food with its antioxidant content. Therefore, it is important to know how the production technology alters the content and composition of these antioxidant compounds. The objective of this study was to collect information on how the increased potassium dominant fertilizer levels and also the additional high-dose fertigation can affect the phytonutrient contents and yields in an orange- and a purple-fleshed sweet potato cultivar. Field experiments were conducted in the Hungarian county of Heves in two consecutive growing seasons in 2021–2022. Different doses of potassium-predominant fertilizer were applied to an orange flesh (Beauregard) and a purple flesh (Stokes Purple) varieties of sweet potatoes. Different application techniques were used in the form of base and top dressing at different rates. The effect on yield and polyphenol content of the different fertilizer rates was investigated. Analytical studies were carried out by high-performance liquid chromatography (HPLC). In the case of the Beauregard variety, in addition to identifying the carotenoids, we also performed their quantitative determination. We found that 87% of the carotenoid content was ß-carotene. The total anthocyanin content was investigated for the purple variety—Stokes Purple, for which a new extraction method was developed. In our study, the split dosages, when the pre-planting fertilizer was supplemented with additional liquid fertilization, resulted in 36 and 30.5% higher yields in the Beauregard in Experiment I and Experiment II, respectively, compared to the untreated control plots over the two years. The additional liquid fertilizer increased the yield to a lesser extent when compared to treatments received only pre-planting fertilizer. As for Experiment III, the split dosages resulted in 34.4% higher yields in the Stokes Purple compared to the control plots. However, the additional liquid fertilizer was not effective at all when the plants received a double dose of pre-planting fertilizer in the case of Stokes Purple. Total carotenoid (Experiment I–II) was higher and anthocyanin yield per plant (Experiment III) was significantly higher in the split-dosage treatment than in the untreated control plots. [ABSTRACT FROM AUTHOR]

A two-year (2010 and 2011) open field experiment was conducted to study the effect of drip irrigation and seasonal variation on the yield parameters and main bioactive components, carotenoids (mainly all trans, cis lycopene, and β-carotene), polyphenols (chlorogenic acid, caffeic acid, gallic acid, quercetin, rutin, naringin, etc.), and tocopherols of processing Strombolino F1 cherry tomatoes. The irrigated plants (STI) gave a higher marketable yield (61% and 101% respectively), and rain fed plants showed a yield loss. Water supply had a strong positive (R=0.98) effect on marketable yield in 2011, but weak (R=0.69) in 2010. In both years, the antioxidant concentration (all carotenoids, total polyphenols, tocopherols) showed a decrease with irrigation. Water supply affected the composition of carotenoids to a considerable extent. The optimum water supply treatment gave a lower proportion of lycopene than the rain fed control (STC) treatment. We observed significant negative correlation between rutin concentration and irrigation. The α-tocopherol concentration was significantly higher in STC treatments. Irrigation negatively influenced antioxidant concentrations of cherry tomato fruits, but higher yield could account for the concentration loss of individual fruits by higher antioxidant production per unit area. [ABSTRACT FROM AUTHOR]

Mycorrhizal inoculations were investigated to reveal their effects on the growth and productivity of processing tomato grown under field conditions. Plants inoculated at sowing (M1), sowing + transplanting (M2) and non-inoculated plants (M0) were grown under regularly irrigated (RI), deficit irrigated (DI), and non-irrigated (I0) conditions. In dry years, under non-irrigated conditions (M2) treatment significantly decreased the canopy temperature, improved the photosynthetic efficiency expressed by chlorophyll fluorescence (Fv/Fm) and the fruit setting, significantly increased the total carotenoids and lycopene concentration of fruits but increased the ratio of green yield. Using deficit irrigation, (M2) plants produced more and larger weighed red fruits than (M1) plants but the β carotene, lutein and lycopene concentration of fruits, except for the vitamin C, decreased. Under severe drought conditions the mycorrhizal inoculations positively influenced the all carotenoids and lycopene concentration of fruits (r = 0.8150, r = 0.7837), but their impact was negative under deficit irrigation. Under water deficiency (I0, DI) the mycorrhizal symbiosis increased the marketable yield and resulted in a 33% increase in green yield and an 18 % increase in the total carotenoids content in dry years but the unmarketable yield decreased. Under water deficiency (M2) treatment produce more marketable yield resulting in 9.8% higher total carotenoids in the tomato fruits than (M1) treatment under field conditions. [ABSTRACT FROM AUTHOR]

Open field experiments were conducted to investigate the effects of plant growth promoting rhizobacteria (PGPR) biofertilizer on processing tomato, grown under three different irrigation regimes. The field effectiveness of rhizobacteria inoculation on total biomass, yield, water use efficiency (WUE), carotenoid, and ascorbic acid production was examined in 2015 and 2016. The experimental design used was randomized block and the number of replications was four for each treatment. There were three different irrigation regimes: rain-fed control (RF), deficit water supply (WS50), and optimum water supply (WS100), which was delivered by drip irrigation in accordance with daily evapotranspiration (ETc). The test was performed on the Uno Rosso F1, processing tomato hybrid. Red fruit were measured at harvest in August and high-performance liquid chromatography (HPLC) was used for analysis. We evaluated yield quantity and total carotenoids and their composition (lycopene and β-carotene) depending on water supplement in 2 years. The marketable yield varied between 14.7 t·ha-1 and 126.9 t·ha-1 depending on treatment. The average soluble solids content (SSC) of the treatments ranged from 3.0 to 8.4. The total carotenoid yields of the treatments ranged from 0.8 to 40.4 kg·ha-1 and the average lycopene yield of the treatments ranged from 0.6 to 34.1 kg·ha-1. The effect of PGPR treatment was clearly positive for harvested yield, but this effect only prevailed under irrigated conditions. [ABSTRACT FROM AUTHOR]

In the fields of human nutrition and the food industry, the various products of the spice red chili pepper have sparked increased attention. The purpose of this study was to determine the quantity and stability of carotenoids, carotenoid esters, tocopherols, and capsaicinoids in new spice chili hybrids under traditional drying utilizing cutting-edge analytical techniques. In both fresh and conventionally dried goods, the quantities and stability of bioactive components vary significantly between the hybrids. The highly pungent cultivar Unijol, which dispersed capsaicinoids 7–9 times more than the other cultivars, had the highest retention of carotenoids (76–138) upon drying. The levels of carotenoids discovered in naturally dried samples were larger in all cultivars than those found in raw materials, indicating continuous over-ripeness processes during long-term drying. Tocopherol stability was ranked Unijol > Hetényi > Unikal, with retention rates of 82–93, 72–79, and 63–73 percent, respectively. The genotypes differed not only in capsaicinoids content, but also in the ratio of capsanthin to dihydrocapsanthin, as well as in their stability during natural and thermal drying, with Unijol being the most stable and Hetényi being the least, with maximal retention of 71–92 percent and 58–86 percent, respectively. • Phytochemicals of new chili hybrids were characterized by recent HPLC, HPLC-MS/MS methods. • Genotype and drying conditions impact on response and stability of phytochemicals in spice chili peppers. • Correlation was observed between pungency and stability of phytochemicals during drying. [ABSTRACT FROM AUTHOR]

Spice peppers have valuable phytonutrients that make them of special interest from nutritional and pharmaceutical points of view. This work was conducted to study the impact of γ-irradiation before over-ripening on phytonutrients of new hybrids of chili peppers. The investigated cultivars were found to significantly differ in their content of capsaicinoids (P < 0.01) and carotenoids (P < 0.05) with Unijol being the richest in pungency and the poorest in the total carotenoid content although its content of bioactive zeaxanthin and β-carotene was the highest. The 3096 μg g-1 fresh weight, which equals 22114 μg g-1 dry weight, and 331710 Scoville Heat Unit (SHU) were recorded for Unijol. The examined cultivars differed significantly in the response of phytonutrients to γ-irradiation treatments. The dose of 2.5 kGy promoted the biosynthesis and stability of capsaicinoids and carotenoids, while the highest dose of 10 kGy decreased, to some extent, the content of phytonutrients except tocopherols. The magnitude of promotion and degradation caused by irradiation was found to be cultivar- and dose-dependent. The highest losses in the total capsaicinoid, total yellow xanthophyll, total red xanthophyll, and total carotenoid content of 19, 34, 37, and 38% respectively were recorded for Unijol as a result of γ-irradiation at 10 kGy. • The Phytonutrients in new hybrids of spice red chilli were characterised and determined. • Irradiated before over-ripening is applied for the first time to enhance quality of spice chilli. • Ɣ-irradiation at 2.5 kGy increases the content and stability of phytonutrients in chillies. • Irradiation at 10 kGy degrades, to some extent, some carotenoids and capsaicinoids, but not tocopherols. [ABSTRACT FROM AUTHOR]