The association of kefir microbiota was observed by electron microscopic examination. Scanning electron microscopic (SEM) observations revealed that kefir grain surface is very rough and the inner portions had scattered irregular holes on its surface. The interior of the grain comprised fibrillar materials which were interpreted as protein, lipid and a soluble polysaccharide, the kefiran complex that surrounds yeast and bacteria in the grain. Yeast was observed more clearly than bacteria on the outer portion of the grain. Transmission electron microscopic (TEM) observations of kefir revealed that the grain comprised a mixed culture of yeast and bacteria growing in close association with each other. Microbiota is dominated by budded and long-flattened yeast cells growing together with lactobacilli and lactococci bacteria. Bacterial cells with rounded ends were also observed in this mixed culture. Kefir grains, kefir suspensions, and kefiran were tested for antimicrobial activities against several bacterial and fungal species. The highest activity was obtained against Streptococcus faecalis KR6 and Fusarium graminearum CZ1. Growth of Aspergillus flavus AH3 producing for aflatoxin B1 for 10 days in broth medium supplemented with varying concentrations of kefir filtrate (%, v/v) showed that sporulation was completely inhibited at the higher concentrations of kefir filtrate (7-10%, v/v). The average values of both mycelial dry weights and aflatoxin B1 were completely inhibited at 10% (v/v). This is the first in vitro study about the antifungal characteristics of kefir against filamentous fungi which was manifested by applying its inhibitory effect on the productivity of aflatoxin B1 by A. flavus AH3.

No abstract

Wheat is one of the most important cereal crops in Egypt. It is consumed at a high level to feed the Egyptian individual because it is relatively cheap compared to other carbohydrate sources. The domestic production of wheat is still insufficient to meet the consumer needs, which increased the food gap of wheat. ), used to evaluate imported wheat to Egypt by several tests like moisture content, test weight, falling number, protein content, shrunken and broken grains and insect damaged kernels.. In general the Ukrainian wheat was the beast among all other wheat originated from France, Romania and Russia, Ukrainian wheat came in the first place in three tests i.e. moisture content, that ranged from 10.88% to 12.43% with an average of 11.46%., test weight, ranged from 78.77 to 80.57 kg hl -1 with an average of 79.70 kg hl -1 and falling number, ranged from 322.0 to 412.0 sec with an average of 360.47 sec., and came in the second order in other tests as, protein content, which ranged from 12.21 to 13.67% with an average 12.80%, shrunken and broken grains ranged from 0.746 to 1.925% with an average of 1.115%. Ukrainian wheat came in the third order in one test like, insect damaged kernels, which ranged from 0.651 to 0.883% with an average of 0.761%.

Wheat is comprised the most important grain and single largest crop by area in Egypt. Despite this fact, Egypt is heavily dependent on imports wheat to meet its consumption needs. The objective of the present study was to determine some mycotoxins (aflatoxin B1, total B1, B2, G1, and G2, ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZON)) in wheat grains imported from four countries (France, Romania, Russia and Ukraine). The tested five samples were obtained from batches imported ate five different times of the year. The results showed that Ukrainian wheat was the beast which contained the least mycotoxins values. Total B1, B2, G1 and G2 of Ukrainian wheat ranged from 0.767 to 1.60 µg.kg -1 , while OTA, DON and ZON were ranged from 0.50 to 1.367, 48.90 to 222.33 and 40.47 to 67.17 µg.kg -1 , respectively.