Effect of pH on protein extraction from sour cherry kernels and functional properties of resulting protein concentrate.

The aims of this research were to examine the effect of pH on extraction of proteins from sour cherry (Prunus cerasus L.) kernels, and to investigate the functional properties of the resulting protein concentrate. The optimum pH values for the protein extraction and isoelectric precipitation were determined as 10.0 and 4.5, respectively. The protein concentrate contained 4.03 ± 0.16% moisture, 3.31 ± 0.17% ash, 2.94 ± 0.36% carbohydrate, 1.93 ± 0.16% lipid, and 80.48 ± 2.38% protein. Water holding capacity, oil holding capacity and the least gelling concentration of the protein concentrate were 2.42 ± 0.09 g water/g, 1.73 ± 0.17 g oil/g and 8%, respectively. Results showed that emulsifying activity and stability indices, foaming capacity and stability of protein concentrate were 38.91 ± 2.50 m2/g, 37.49 ± 2.41 min, 35.00 ± 3.54% and 71.80 ± 7.25% (after 30 min), respectively. The functional and chemical properties of the protein concentrate indicate that it may find application as functional ingredient for various food products.

Aflatoxins in dairy cow feed, raw milk and milk products from Turkey.

This study aims to detect aflatoxins (AFs) in dairy cow feed, milk and milk products using a high-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method. All the validation parameters met the method performance criteria of the European Union. The samples comprised 76 dairy cow feeds and 205 milk and milk products (including yoghurt and yoghurt-based beverage, ayran). AFs were present in 26.3% of the feed samples. Two feed samples exceeded the maximum limit (ML) of 5 µg kg(-1) for AFB1 as established by the EU. Nineteen milk samples (21.1%) contained aflatoxin M1 (AFM1) of which three exceeded the EU ML of 0.05 µg l(-1). In addition, only two yoghurt samples and one ayran sample contained AFM1, but the levels were lower than the EU ML.