Color of sun-dried tomato is an important quality criteria and color stability of sun dried tomatoes is affected by storage conditions such as temperature, time and packaging type. The objective of this study was to investigate the effects storage time, storage temperature and packaging type on color stability of sun-dried tomatoes by using factorial experimental design. In this study, the 2 3 factorial design was used to represent mathematical relationship between the storage conditions and color values (L and a/b) and used to verify whether or not factor variables of storage conditions are effective on color. Results in experimental model showed that all factors had negative effects on the color values which indicated the reducing stability of color. The main effect was found to be the time having the highest coefficient (-3.3 for L and-0.12 for a/b) in design models and storage temperature was found to be the least effective factor. Design model and response surface plots revealed that storage temperature could be kept around 20°C for 9 months and storing under vacuum packaging should be selected to reduce color losses for the safe storage conditions.

This study aimed to optimize the extraction conditions for Sorbus umbellata (Desf.) Fritsch var. umbellata leaves to maximize the phenolic content and their antioxidant activity and to investigate β-glucuronidase (GUS) enzyme inhibitory, antimicrobial and cytotoxic potentials of the extracts obtained under optimum conditions. The optimum extraction conditions were found to be 78.2 and 79.7% solvent, 73.1 and 71.5°C, and 89.9 and 88.8 min to maximize phenolic content and antioxidant activity, respectively. Low values of coefficient of variations indicate the high reliability and reproducibility of the conducted extraction experiments. Bioactivity results showed that extracts had cytotoxic effect on the MCF-7 and A549 cells where the highest cell proliferation inhibition was observed for the A549 cell line (71.8% at 150 μg/mL). Staphylococcus aureus showed highest zone of inhibition (19.3 mm) in all bacteria followed by Escherichia coli. Additionally, extracts displayed potential GUS inhibitory activity. In conclusion, Sorbus umbellata leaf extract can be obtained by optimized cost-saving extraction and has a potential bioactivity to be utilized as a food ingredient for high value-added products and/or nutraceuticals development where it can combat oxidative stress and GUS mediated reactive metabolite formation.

The aim of this study is to obtain the grape seed extract with high antioxidant activity and to investigate the quality characteristics of traditional yogurts fortified with seed extracts at different concentrations. For this aim, batch hot water extraction was conducted and extraction conditions were optimized to produce Vitis vinifera L. grape seed extract using with the highest antioxidant activity. The fortification of yogurts was conducted at 0.1-0.15 and 0.2 g/ 100g extract level and antioxidant, physicochemical, microbial and sensory characteristics of the yogurt samples were analyzed. Results showed that antioxidant activity of fortified yogurts were higher and up to 14 % more antioxidant activity was detected compared to the control samples. Yogurt samples preserved their physicochemical characteristics. Although sample with 0.1 g/100 g extract had highest scores in overall acceptance, the sample containing the highest extract concentration of 0.2 g/100 g, exhibited negative perceptions by panelists in sensorial analysis. In conclusion, grape seed may be used in traditional yogurt production by improving the taste and antioxidant potential. The fortification levels of 0.1-0.15 g/100 g grape seed extract might be more feasible in functional yogurt production and might be more recommended for consumer's appreciation in terms of positive health effects.