Effect of Different Method of Drying of Five Varieties Grapes (Vitis vinifera L.) on the Bunch Stem on Physicochemical, Microbiological, and Sensory Quality

Abstract

The influence of the drying technique on certain quality attributes of dried grapes was analysed. Five varieties of grape were used in this study (Bezsemenné, Perlette, Vrboska, Beauty seedless, and Jakubské). All the varieties were dried using four methods: drying at 40 °C, combined drying (70, 65, and 60 °C), drying at 70 °C, and lyophilisation. The quality attributes such as total soluble solids, water activity, content of vitamin C, the colour parameters (L*, a*, b*), and microbiological (colony forming units, moulds, yeasts) and sensory (smoothness, gloss, colour, odour, chewability, juiciness, flavour, and overall impression) analysis were determined, depending on the method of drying. Lyophilised grapes from the Jakubské variety had the highest vitamin C content. They contained 0.58 mg of vitamin C per 100 g of dried grapes. However, no significant differences between varieties in vitamin C content were found. This confirmed concerns about the negative impact on the nutritional quality of dried grapes with increasing temperature. The lowest total count of microorganisms (CFU), moulds, and yeasts were determined after using highest drying temperature (70 °C). Higher CFU values were determined in lyophilised grapes, and then followed by grapes dried at 40 °C. Lyophilised grapes and grapes dried at 40 °C achieved the best sensory rating in general. The final product was intended to have a unique appearance while maintaining the evaluated quality parameters.

Drying Grapes after the Application of Different Dipping Solutions: Effects on Hormones, Minerals, Vitamins, and Antioxidant Enzymes in Gök Üzüm (Vitis vinifera L.) Raisins

“…Keskin et al [35] stated that the vitamin C in different grape varieties ranges from 6.38 mg 100 g FW −1 (Katıkara variety) to 12.83 mg 100 g FW −1 (Isabella variety). Langová et al [36] reported that the concentration of vitamin C ranges from 0.0 to 0.58 mg 100 g −1 in different raisin varieties, such as Bezsemenné, Perlette, Vrboska, Beauty seedless, and Jakubské. These results are lower than those reported from the Gök Üzüm variety in this trial.…”

Effect of pre-treatments on qualities and storage life of banana dried by using solar dryer dome

“…Regarding to dried food products, the color property was an element of controlling and standardizing the final product [16]. Surface color determination for quality evaluation based on visual grading by trained humans was a common practice in the production of dried banana.…”

Metabolism and Regulation of Ascorbic Acid in Fruits

“…The main dietary sources of AsA for humans are fruits. The AsA contents of some fruits are organized, such as tomato, kiwifruit, orange, strawberry, carrot, sweet pepper, and so on (Table 1) [18][19][20][21][22][23][24][25][26][27][28][29][30]. Because of the important role of AsA in plants, in-depth studies have been carried out on the metabolic pathways of AsA in plants (Figure 1).…”