Gundogdu, E.; Tanriverdi, E.; Yildiz, H.

In this study, the antimicrobial effect of Coriandrum sativum L. leaves against 30 different foodborne microorganisms, including 20 bacteria, 7 fungi, and 3 yeast species was tested, and some microbiological properties of yoghurt produced with lyophilized C. sativum L. were investigated. Yoghurts were prepared at three different concentrations of C. sativum L. powder (0.1, 0.2, and 0.3% w/w) and stored at 4°C for 21 days. Ethanol extract of the fresh plant showed antimicrobial activity against only 9 bacteria and 1 yeast with different inhibition zone diameter changing from 8 to 12 mm, but had no effect on moulds used in this study. The addition of C. sativum L. had no statistical significance on the growth of yoghurt bacteria compared with the control sample and they remained over 8 log CFU g-1 in all yoghurts throught the storage period. On the other hand, an increase was observed in the number of Lactobacillus bulgaricus and a decrease in the number of Streptococcus thermophilus depending on the concentration of C. sativum L., but this was not statistically significant (P> 0.05). However, significant differences in yeast and mould counts were observed (P< 0.05). Yeasts and moulds were not detected in any of the samples containing C. sativum L. powder, whereas the counts of yeast and mould increased in control throught the storage period. These results show that the powder of C. sativum L. leaves can be used an agent for preventing the growth of yeast and mould, which are shelf-life and quality spoilage microorganisms of yoghurt.

Engül, M.S.; Erkaya, T.; Yildiz, H.

The effect of adding strawberry pulp to yogurt on its physicochemical properties, antioxidant activity and sensory characteristics was studied. For this purpose, experimental yogurts were produced by the addition of strawberry pulp (at 8, 12 and 16%) to plain yogurt and analyses were carried out through 14 days of cold storage. The titratable acidity and viscosity values of yogurts increased with the increasing of strawberry pulp concentration. Conversely, the total solid, fat, protein, ash, pH and syneresis values decreased. Antioxidant activity (β-caroten bleaching assay) and IC50 (DPPH radical scavenging assay) in yogurts ranged from 77.71 to 86.12%, 205.70 to 2241.09 μg /mL during storage, respectively. For the sensory properties of yogurts, yogurt including 16% of strawberry pulp received the highest overall acceptability score on the first day of storage.

Ercisli, S.; Sengul, M.; Yildiz, H.; Sener, D.; Duralija, B.; Voca, S.; Dujmovic Purgar, D.

Eleven medlar {Mespilus germanica L.) genotypes sampled from Turkey were analyzed for their fruit weight, fruit dimensions, fruit firmness, ostiole diameter, shape index, skin color, moisture (%), ash (%), reducing sugar (%), crude protein (%), pH, soluble solid content (%), vitamin C (mg/100 g), minerals (P, K, Ca, Mg, Fe, Zn, Mn), total phenolic content and total antioxidant capacity. A wide variation among genotypes on most of the searched parameters was evident. Fruit weight varied from 11.21 g to 33.24 g indicating high variability among genotypes. Determination of antioxidant activities by β-carotene - linoleic acid and 2-diphenyl-l-picrylhydrazyl (DPPH) free radical scavenging assays resulted in average 80.8%, and 46.6 μg/ml FW DPPH, respectively. The total phenolic contents of eleven medlar genotypes varied from 114 to 293 mg gallic acid equivalent in 100 g fresh weight basis. The medlar fruits were found to be rich in terms of potassium, calcium, phosphorus, magnesium and iron.