In broiler chickens, the relationship between dietary supplementation of vitamin C and hepatic, cardiac and renal heat shock proteins (HSP60, HSP70 and HSP90), heat shock factors (HSF-1 and HSF-3) and enzymatic antioxidants requires further investigation. The current study aimed to investigate this relationship at cellular and molecular levels in a 42 days experiment. Two hundred, one-day-old broiler chicks (Ross 308) were allocated into four equal groups. Chicks in the first and third groups were thermo-neutral (TN; 22°C for 24 hours/day) and fed basal diet without or with vitamin C (1g/kg basal diet), respectively. Chicks in the second and fourth groups were heat stressed (HS; 34°C for 8 hours/day) and fed basal diet without or with vitamin C, respectively. Performance parameters were recorded throughout the experiment. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPX), Catalase (CAT) and gene expression of heat shock proteins (HSP60, 70 and 90) and heat shock factors (HSF 1 and 3) were analyzed in liver, heart and kidney tissues of the studied groups. Heat stress induced a negative impact on performance parameters, significant reduction in activities of all examined antioxidant enzymes and a significant up-regulation in heat shock proteins and factors genes in all studied tissues. Dietary supplementation of vitamin C corrected these parameters towards the normal control values. Conclusively, dietary supplementation of the examined dose of vitamin C was efficient at ameliorating the detrimental effects of heat stress on liver, heart and kidney tissues of broilers chickens at cellular and molecular levels.

Effects of infrared power output and sample mass on drying behaviour, colour parameters, ascorbic acid degradation, rehydration characteristics and some sensory scores of spinach leaves were investigated. Within both of the range of the infrared power outputs, 300–500 W, and sample amounts, 15–60 g, moisture content of the leaves was reduced from 6.0 to 0.1±(0.01) kg water/kg dry base value. It was recorded that drying times of the spinach leaves varied between 3.5–10 min for constant sample amount, and 4–16.5 min for constant power output. Experimental drying data obtained were successfully investigated by using artificial neural network methodology. Some changes were recorded in the quality parameters of the dried leaves, and acceptable sensory scores for the dried leaves were observed in all of the experimental conditions.

Ascorbic acid is a well-known antioxidant found in plants. The content of ascorbic acid was assayed using a normal phase European Pharmacopoeia HPLC method for ascorbic acid in medicinal products. The content of ascorbic acid in herbs was calculated in % for absolutely dry drug. Ascorbic acid was not detected in the roots of Primula ueris, in aerial parts it was detected in flowers (0.43 +/- 0.034%), in blades (1.43 +/- 0.11%) and petioles (1.56 +/- 0.12%). In fresh leaves collected at weekly intervals the content of ascorbic acid varied from 1.19 to 2.39%, being highest from mid-May to mid-June. The fresh leaves contained 2.35 +/- 0.18% of ascorbic acid and when frozen its content was quite stable for one year. The content of ascorbic acid in dried leaves decreased more than ten times in three months, in twelve months it was less than 1/20th of the initial level. Compared to the analyzed common fresh fruits and salads (n = 10) the fresh leaves of common cowslip contained considerably more ascorbic acid. Commercial orange juices could be recommended as the most convenient source of ascorbic acid (8.6-50.4 mg/100 ml); 1-5 glasses of orange juice could fulfill the recommended daily intake of vitamin C (60 mg).