Hüseyin Gençcelep

Determination of biogenic amines in fish products

Concentrations of 5 biogenic amines were simultaneously determined in 63 samples of fish products using HPLC. Fish products were purchased from different cities in Turkey. Fish samples included canned sardines, canned mackerel, canned tuna, and marinated anchovies. The total level of biogenic amines ranged from 26.58 to 406.55 mg/kg. Histamine (HIS) and cadaverine (CAD) were the dominant biogenic amines. Concentrations of tyramine (TYR) and HIS were less than 50 and 100 mg/kg, respectively. The relationship between formation of biogenic amines in fish products and thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), and pH values was also investigated. There were significant negative correlation (p<0.01) between TBA, and TVB-N, pH respectively. Significant positive correlation was found between TVB-N, and pH, protein, and CAD, TYR, and HIS. There were significant (p<0.01) positive correlations between TBA, TYR, tryptamine, pH, and TVB-N values in fish samples.

Evaluation of the Nutritional and Storage Quality of Meatballs Formulated with Bee Pollen

In this study, the nutritional and storage quality of meatballs formulated with different levels (0, 1.5, 3.0, 4.5 and 6.0%) of bee pollen were investigated during storage at 41℃ for 9 d. Protein content of meatballs increased, while moisture content decreased with increased pollen. The addition of pollen improved cooking loss but decreased the redness (Hunter a value) and sensory scores. Textural parameters (hardness, springsness, gumminess, and chewiness) were affected by pollen addition and the hardness and gumminess values of meatballs decreased as the pollen content increased. While C18:0 content of meatballs slightly decreased with pollen addition, C18:2n-6c, C18:3n-3, C20:5n-3, and PUFA contents increased. The PUFA/saturated fatty acids (P/S) ratio increased from 0.05 in the control to 0.09 in meatballs with 6.0% pollen. The n-6/n-3 ratio decreased from 11.84 in the control to 3.65 in the meatballs with 6.0% pollen. The addition of pollen retarded the lipid oxidation and inhibited the bacterial growth in meatballs. The pH, redness, TBA value and total aerobic mesophilic bacteria, coliform bacteria and S. aureus counts values changed significantly during storage. The results suggest that bee pollen could be added to enhance the nutritional and storage quality of meatballs with minimal changes in composition and/or sensory properties.

Effects of bay leaf (Laurus nobilis) and green tea (Camellia sinensis) extracts on the physicochemical properties of the marinated anchovies with vacuum packaging

ABSTRACT Green tea and bay leaf extracts are natural preservatives for increasing the shelf life of food products. Effects of green tea and bay leaf extract on anchovy marinades were determined by measuring microbiological, sensory, and physical properties. Marinated anchovies were prepared with 4.2% wine vinegar, 9% salt solution and ripened for 24 h at 10°C in a fish processing factory. Green tea extract (1%, 2% w/v), bay leaf extract (0.1%, 0.2 w/v) were added to the marination solution. Following the draining procedure, marinated anchovies were vacuum packaged and stored at 4°C for 240 days. The addition of green tea and bay leaf extract reduced microbial load, TVB-N (total volatile basic nitrogen) level, and TBARS (thiobarbituric acid reactive substances) value. Green tea extract was most effective on lipid peroxidation and yielded a darker color, which is not preferred by customers. Biogenic amines amount in all of the samples were very low due to low acidity level and good manufacturing practices. Plant extracts had no significant effect on biogenic amine accumulation in marinated anchovies.

THE EFFECT OF DRIED MUSHROOM (AGARICUS BISPORUS) ADDITION ON MICROBIOLOGICAL QUALITY AND BIOGENIC AMINE CONTENTS IN SUCUK PRODUCTION

The aim of this study, the effect of addition to mushroom into sucuk at different concentrations (0, 0.5, 1 and 2%) on microbiological quality and biogenic amine formation were investigated at different ripening periods (0, 3, 6, 9 and 12 days). Tryptamine and phenylethylamine were found 11.42 and 42.96 mg/kg beginning of ripening time, respectively. Both mushroom concentration and ripening period had significant (P <0.01) effect on lactic acid bacteria (LAB), Micrococcus and Staphylococcus counts and pH. The Enterobacteriaceae, yeast and mould counts were found to be under the detectable level (<log 2.0 cfu/g) after the 3rd day of ripening period. The pH value was determined as 5.82 at the beginning of ripening time and decreased to 4.82 at the end of ripening (12 days). These results suggest that mushroom can be used as a natural functional ingredient to improve taste and flavor as well as shelf-life stability of sucuk.