Records of Agricultural and Food Chemistry

The GC-FID and GC-MS analysis of the essential oil of areal parts of Salvia plebeia, led to identification of 32 compounds constituting 93.8 % of the essential oil (EO). EO of this plant was dominated by sesquiterpenoids (49.4%) with major presence of β-caryophyllene, furanogermenone, germacrone and 14-hydroxy-α-humulene. Antioxidant activity determined by DPPH and super oxide radical scavenging, metal chelating and reducing power assay, though the EO showed lower activity than the standard antioxidants but possessed significant reducing power. The in vitro antifungal activity of EO against phytopathogens was determined by poisoned food method. EO showed strong inhibitory effect on the mycelial growth against all phytopathogens with an IC50 values ranging from 180.5 to 372.9 µg/mL and MIC ranging from 1500 to 3000 µg/mL. Among the test fungi, three fungi, viz., Helminthosporium maydis, Curvularia lunata and Albugo candida were highly susceptible for the oil in spore germination assay with their IC50 value 246.9, 263.8 and 316.8 µg/mL, respectively.

Water kefir is produced by fermenting a plant-based carbon source with water kefir grains under favorable conditions. The resulting drink had unique sensorial properties, high antioxidant capacity, and probiotic microorganism content. In this study, water kefir grains were used for fermentation of nectar obtained from Viburnum opulus for 24 hours at 25°C. The study investigated the fermented beverage's organoleptic, physico-chemical, antioxidant capacity, and microbiological content. The results showed that the sensory evaluation of the water kefir beverage obtained by fermenting V. opulus was generally low, but the product's color and fermented odor were highly appreciated. Lactobacilli spp., Lactococci spp., and yeast counts were approximately 6 log cfu/mL after fermentation. Even though the total soluble solids amount value was as low as 1.0, the microbial development in the plant nectar was favorable.  Following the fermentation, there was a significant increase in the concentrations of malonic acid, lactic acid, citric acid, and propionic acid (P<0.05). Our sample color had a slightly red-yellow mixture based on instrumental color analysis. The total antioxidant capacity was determined as 937 mg GAE/L based on the results of the antioxidant capacity analysis. The conclusion was that V. opulus is a suitable substrate for fermentation with water kefir grains despite the low overall sensorial evaluation of the product.

Abstract:  Sodium benzoate is a widely used food preservatives and its determination receives much interest. This article describes the development and validation of a method using a UV-VIS-NIR Spectrophotometer at 225 nm to determine the mass fraction of sodium benzoate in water for the purpose of characterization of a reference material. The study was carried out in accordance with the ICH and EURACHEM guides using a primary reference material of sodium benzoate of purity 99.98±0.22%. The studied performance characteristics were the limit of detection (LOD), limit of quantification (LOQ), selectivity, linearity, accuracy, precision, recovery and bias. The results obtained were statistically analyzed and the method showed very good linearity in the selected calibration range. The LOD and the LOQ were found 0.19 and 0.57 mg/kg respectively. This method demonstrated very good accuracy ranging from 99.54 to 100.08% and precision, 0.39% RSD, signifying its high reliability in producing precise and accurate results. The validation results also revealed that the method is fit-for-the purpose of determination of sodium benzoate in water.