KEEPING QUALITY OF DIFFERENT PACKAGED SALTED ATLANTIC BONITO "LAKERDA"

Quality and shelf life of salted Atlantic bonito (lakerda) packaged in brine, under vacuum and in oil conditions and stored at 4  ±  1C were studied. The sensory scores of lakerda stored in all package types at 4C were 14 weeks, respectively. The microbiological count of the vacuum-packaged lakerda was extended than that lower of other group sample. Overall results of this study showed that 9 weeks of storage of lakerda in brine was the beginning of spoilage, whereas storage of samples in oil and vacuum package delayed onset of spoilage about 2–3 weeks in terms of chemical analysis. Lakerda stored in cold storage as sensory, chemical and microbiological results for brine- and oil-packaged lakerda showed us that week 11 was the beginning of spoilage, and for vacuum-packaged lakerda, week 13 was the beginning of spoilage.

PRACTICAL APPLICATIONS

Raw fish and processed fish product is highly perishable and has a short shelf life. Packing processing is finding increasing use in the food industry because of its relative advantages versus other food processing methods in eliciting minimal changes in the flavor, microbiological and nutritional qualities of the final product. This paper illustrates the changes induced in salted fish by packaging at different types. By using oil- and vacuum-packaged treatment, shelf life of traditional-packaged (in brine) lakerda could be extended at 4C from 9 weeks to 11–13 weeks.     

CHANGES IN BIOCHEMICAL AND MICROBIOLOGICAL CHARACTERISTICS OF TURKEY SUCUKS AS AFFECTED BY PROCESSING AND STARTER CULTURE UTILIZATION

The effects of starter culture and processing on the microbiological and biochemical characteristics of turkey sucuk were studied during production and storage. No differences ( P >  0.05) in proximate composition and salt contents were found in sucuks produced either by traditional or heated methodologies. Both traditional ( P <  0.05) and heat-processed ( P >  0.05) sucuks that incorporated S1 had the lowest pH value, and thus the highest titratable acidity. Heating process resulted in about 1 log unit reduction in yeast counts and 1.5 log unit reduction in lactic acid bacteria, total mesophilic aerobic bacteria and micrococci–staphylococci counts of all sucuks. Within the heat-processed sucuks, heating stage did not result in a significant change in nonprotein nitrogen contents ( P >  0.05). Changes in myofibrillar and sarcoplasmic protein were observed because of proteolytic changes during ripening, but, in general, no major difference was observed between sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns as a result of starter culture treatments.

PRACTICAL APPLICATIONS

Results of this study can be applied to improve some biochemical and microbiological characteristics of fermented turkey sausages. The findings showed that utilizing commercial starter culture mix, containing Lactobacillus sake, Staphylococcus carnosus and Staphylococcus xylosus II resulted in lower pH value with a higher titratable acidity than traditional style-fermented turkey sausages. These parameters are responsible for texture development and characteristic taste of fermented sausages.     

ACID PH PRODUCED BY LACTIC ACID BACTERIA PREVENT THE GROWTH OF BACILLUS CEREUS IN BOZA, A TRADITIONAL FERMENTED TURKISH BEVERAGE

The growth and survival of Bacillus cereus, a known pathogen commonly found in cereals, during lactic acid fermentation of boza, a traditional Turkish cereal beverage, was studied. In the boza base inoculated with both the starter culture and B. cereus, the acidity developed to pH 2.6 and 0.8% titratable acidity after 72 h; the growth of B. cereus was reduced from 3.9 log cfu/mL to 1 log cfu/mL within 72 h. The control boza base to which starter was not added had a pH of 3, titratable acidity of 0.8%. The B. cereus in this boza base to which no starter culture was added dropped to 1 log cfu/mL after 72 h. No strains of lactic acid bacteria were found to produce bacteriocins antagonistic to B. cereus. Low pH and acidity were found to be the major factors inhibiting growth of B. cereus in boza.     

CHANGES IN Pb, Cd, Fe, Cu AND Zn LEVELS DURING THE PRODUCTION OF KAŞAR CHEESE

ABSTRACT

Levels of Pb, Cd, Fe, Cu and Zn in milk, curd, pressed curd, fresh cheese, whey, rennet and scalding water taken from two different Ka?ar cheese plants (A and B) in Ankara, Turkey were investigated. The milk used in plant A contained higher amount of Pb, Fe and Zn than the milk used in plant B. Pb level during processing in both dairy plants showed a significant increase from milk to curd (626.2–912.3 µg/kg for plant A and 265.2–371.8 µg/kg, dry weight, for plant B) (P < 0.01). Similarly, Fe, Cu and Zn contents of the curds in plant A and B showed an important increase with respect to the milk (P < 0.01). During transition of the curd to pressed curd and of pressed curd to fresh cheese, almost all metals tested showed a decrease because of the loss of these metals into whey and scalding water. The results showed that curdling the milk was the most important contamination step.

PRACTICAL APPLICATIONS

Heavy metals may enter the human body through food, water, air or absorption through the skin, and can cause metabolic anormalies. Heavy metals may reach our foods from a number of sources. The more important of these are: soil; the chemicals applied to agricultural land; the water used in food processing or cooking; and the equipment, containers and utensils used for food processing, storage or cooking. Milk and milk products are the basic components of the human diet, and among milk products cheese holds an important place. Ka?ar cheese ranks second with respect to consumption, significantly contributing to the Turkish diet. In order to prevent the health risk of consuming contaminated cheeses, it is very important to determine the effect of equipment and process variation on the heavy‐metal content of Ka?ar cheese. The results of this study would help the regulatory authorities to establish a Hazard Analysis and Critical Control Points (HACCP) plan and to identify important contamination sources for Ka?ar and similar kind of cheeses.

     

SEQUENTIAL TREATMENTS OF HOT WATER AND MODIFIED ATMOSPHERE PACKAGING IN CHERRY TOMATOES

ABSTRACT

The effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on the storage and fruit quality of cherry tomatoes (Lycopersicon esculentum Mill. cvs. “Alona” and “Naomi”) were investigated. For this purpose, light‐red cherry tomato fruits were dipped in hot water (54C for 5 min) and subsequently stored in plastic film materials with various O₂ and CO₂ permeabilities. The cultivars used in the study were stored in a cold room at 5–7C and 90 ± 5% relative humidity (RH). The changing gas composition within the films and quality changes of the fruits were evaluated during the storage period. At the end of the study, HWT combined with MAP produced better results than MAP alone in both cultivars. Therefore, the HWT + MAP treatment proved effective with regard to fruit quality and delaying the maturity of cherry tomatoes during storage. HWT + 50 micropolyethylene (μPE) treatment produced the best result in the two cultivars at the end of the 28‐day storage with respect to the parameters evaluated in the study.

PRACTICAL APPLICATIONS

Tomato is considered a climacteric fruit, in which ripening is accompanied by a peak in respiration and a concomitant sharp increase in ethylene production, which accelerates quality loss through the physicochemical changes related to this process, such as softening and color evolution. Postharvest heating is a noncontaminating physical treatment that delays the ripening process, reduces chilling injury and controls the activity of pathogens. Because of these beneficial effects, heat treatments are currently used commercially for quality control of fresh products. Modified atmosphere packaging is another technique that has been used to prevent or retard postharvest fruit ripening and its associated biochemical and physiological changes by favorably altering the O₂ and CO₂ levels around the products. In recent years, the use of combined techniques in the postharvest handling of fresh products is increasing, and numerous authors have obtained good results using a combined treatment. Diseases have the potential to destroy the market value and utility of large amounts of fresh tomato annually. The present work evaluated a prestorage conditioning treatment to protect against these losses. The results will allow the long storage of cherry tomato, benefiting the growers, exporters, shippers and distributors of this horticultural product.

     

Effects of coagulant type on the physicochemical and organoleptic properties of Kashar cheese

Kashar cheeses were manufactured using different coagulants (calf rennet, chymosin derived by fermentation and proteases from Rhizomucor miehei and Cryphonectria parasitica) and ripened for 90 days. Use of different coagulants did not influence the dry matter, fat, protein, salt, pH, titratable acidity, total free fatty acids and texture profile analyses. The levels of water‐soluble nitrogen, 12% trichloroacetic acid‐soluble nitrogen, and for 5% phosphotungstic acid‐soluble nitrogen, the sensory properties were significantly influenced by the use of different coagulants. β‐casein was more hydrolysed in the cheese manufactured using protease from Cryphonectria parasitica than the other cheeses during 90 d of ripening.     

REDUCTION OF PATULIN IN APPLE JUICE CONCENTRATES DURING STORAGE

In this study, the reduction of patulin content in apple juice concentrates during 6 months of storage at 22 and 30C was investigated. Results demonstrated that reduction in patulin content was dependent on the storage temperature and time. Patulin reductions after 1 month of storage at 22 and 30C were in the ranges of 45–64% and 66–86%, respectively. Levels of patulin were below detectable limits after 4 months of storage at 22 and 30C.     

STUDY OF THE STEADY FLOW BEHAVIOR OF HAZELNUT PASTE

The steady flow behavior of five different hazelnut pastes was studied and compared. Among the three steady shear geometries tried; cone and plate, plate and plate and concentric cylinder, the concentric cylinder was found to produce the most consistent data. Generated data were used to test the applicability of possible rheological models. Power Law Model could correlate the data very successfully. Yield stress values determined were quite low and application of Herschel-Bulkley Model did not improve the correlation significantly. The temperature dependency of the flow behavior was also studied obtaining data at four different temperatures. Correlations for temperature dependency were incorporated into the rheological model equations and these models were used to estimate pumping power requirements for pipe flow.