Formation of heterocyclic aromatic amines in doner kebab cooked with different methods at varying degrees of doneness.

This study was designed to determine the formation of heterocyclic aromatic amines (HCAs) in two different types of doner kebab (yaprak doner-YD or mix doner-MD) cooked with different cooking methods (gas or electric) at varying degrees of doneness (rare, medium, well-done). In doner samples, nine common HCAs (IQ, IQx, MeIQ, MeIQx, PhIP, 4,8-DiMeIQx, 7,8-DiMeIQx, AαC, MeAαC) were detected. Additionally, the changes in the HCA precursors were evaluated. The initial concentration of precursors gradually decreased with the increase in doneness degree due to degradation or possible contribution in the Maillard reaction to form HCA compounds as a result of heat treatment (p < 0.05). Creatine content decreased, while creatinine content increased because of the conversion reaction. The two most abundant HCA in doner samples were 4,8-DiMeIQx and IQ, which measured in the range of 0.020-2.865 ng g-1 and 0.052-0.513 ng g-1, respectively. Other detected HCAs were determined in especially well-done samples. In conclusion, the diversity and the amount of each HCA compound in doner kebab samples showed variation depending on the effect of doneness degree, doner kebab type or cooking methods (p < 0.05).

Microwave thawing and green tea extract efficiency for the formation of acrylamide throughout the production process of chicken burgers and chicken nuggets.

BACKGROUND: Initially, we measured the acrylamide (AA) levels of chicken burgers (CBs) and chicken nuggets (CNs) purchased from fast food restaurants. After the determination of AA in these products, we aimed to investigate whether the use of green tea extract in the covering material, and microwave thawing before frying, mitigated the formation of AA in CBs and CNs during the production process. RESULTS: According to our study, AA concentrations of CBs and CNs purchased from fast food restaurants were in the range of 13.43-118.97 and 32.92-134.90 ng g-1 coating, respectively. In our experiment, AA levels varied between 19.61 and 40.08 ng g-1 coating for CBs and 7.92-49.60 ng g-1 coating for CNs. Green tea extract reduced the AA formation in CBs and CNs at the pan frying and steam oven cooking heat treatment steps (P < 0.05). However, microwave thawing did not affect AA level of CBs and CNs. CONCLUSION: When the AA levels of commercial CBs and CNs are compared with those produced in our experiment, the use of green tea extract could be a novel, easy and practical application for fast food producers to minimise AA levels in the first two steps of the production without changes to the sensory properties of the final products. © 2016 Society of Chemical Industry.

The Comparative Effect of Carrot and Lemon Fiber as a Fat Replacer on Physico-chemical, Textural, and Organoleptic Quality of Low-fat Beef Hamburger.

This study was designed to determine the usability of lemon fiber (LF-2%, 4%, 6%) and carrot fiber (CF-2%, 4%, 6%) to produce low-fat beef hamburgers. To that end, a certain amount of fat was replaced with each fiber. The proximate composition, pH value, cholesterol content, cooking characteristics, color, texture profile, and sensory properties of low-fat beef hamburgers were investigated. LF increased moisture content and cooking yield due to its better water binding properties, while CF caused higher fat and cholesterol contents owing to its higher fat absorption capacity (p<0.05). LF resulted in a lighter, redder, and more yellow color (p<0.05). Hardness, gumminess, springiness, and chewiness parameters decreased when the usage level of both fibers increased (p<0.05). However, more tender, gummy, springy, and smoother hamburgers were produced by the addition of CF in comparison with LF (p<0.05). Moreover, hamburgers including CF were rated with higher sensory scores (p<0.05). In conclusion, LF demonstrated better technological results in terms of cooking yield, shrinkage, moisture retention, and fat retention. However it is suggested that CF produces better low-fat hamburgers since up to 2% CF presented sensory and textural properties similar to those of regular hamburgers.

Lipolytic Changes in Fermented Sausages Produced with Turkey Meat: Effects of Starter Culture and Heat Treatment.

In this study, the effects of two different commercial starter culture mixes and processing methodologies (traditional and heat process) on the lipolytic changes of fermented sausages manufactured with turkey meat were evaluated during processing stages and storage. Free fatty acid (FFA) value increased with fermentation and during storage over 120 d in all fermented sausage groups produced with both processing methodologies (p<0.05). After drying stage, free fatty acid values of traditional style and heat processed fermented sausages were between 10.54-13.01% and 6.56-8.49%, respectively. Thiobarbituric acid (TBA) values of traditionally processed fermented sausages were between 0.220-0.450 mg·kg(-1), and TBA values of heat processed fermented sausages were in a range of 0.405-0.795 mg·kg(-1). Oleic and linoleic acids were predominant fatty acids in all fermented sausages. It was seen that fermented sausage groups produced with starter culture had lower TBA and FFA values in comparison with the control groups, and heat application inhibited the lipase enzyme activity and had an improving effect on lipid oxidation. As a result of these effects, heat processed fermented sausages had lower FFA and higher TBA values than the traditionally processed groups.

The effects of tumbling and sodium tripolyphosphate on the proteins of döner.

This study was designed to investigate the influence of tumbling and sodium tripolyphosphate (STPP) with marination on the protein structure of raw and cooked döner, a traditional Middle East product consumed widely in many areas of the world. Proximate composition (%moisture, %protein, %fat, %ash, and pH value), salt soluble protein (SSP) and total α-amino grup amount were determined. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to investigate alterations in the sarcoplasmic and myofibrillar proteins. Utilization of STPP increased the moisture content and ash contents, and pH value of raw döner (p<0.05). Only tumbling and STPP had a significant two-way interaction for moisture content, SSP and total α-amino group amounts of cooked döner (p<0.05). None of the treatments significantly affected the fraction of sarcoplasmic and myofibrillar proteins. In addition, cooking caused proteolysis of these proteins.

The effects of carrageenan and pectin on some quality characteristics of low-fat beef frankfurters.

Effects of carrageenan (0.3, 0.5, or 0.7%) and carrageenan (0.3, 0.5, or 0.7%) with a pectin gel (20%) on some quality characteristics of low-fat beef frankfurters were evaluated in comparison to a high-fat control (HFC) and a low-fat control (LFC). While low-fat frankfurters had <3.0% fat, 73-76% moisture, 13-14% protein, HFC had 17% fat, 59% moisture, and 14% protein. A reduction of 50-59% in cholesterol was determined in low fat beef frankfurters as compared to HFC (P<0.05). Better process yield and emulsion stability, and less purge were observed with increasing carrageenan concentration. Treatment groups showed higher water holding capacity (WHC) than LFC, and lower WHC than HFC (P<0.05). With increasing carrageenan concentration, WHC increased and penetrometer value decreased in low-fat frankfurters.

Storage stability of low-fat beef frankfurters formulated with carrageenan or carrageenan with pectin.

Storage stability of low-fat frankfurters (<3.0 fat content) formulated with carrageenan (0.3, 0.5, and 0.7%) or carrageenan with a pectin gel (PG) (20%) was examined during 49-day refrigerated storage. Low fat frankfurters had higher bacterial growth than high-fat control (HFC) over the refrigerated storage due to higher water activity resulting from extra water addition. While there was no change in the pH of low-fat frankfurters initially due to carrageenan or PG incorporation, the most noticeable pH decline was observed in PG-added frankfurters followed by only carrageenan added ones over the storage period. HFC had the highest (P<0.05) TBA value and the lowest redness index (a(∗)/b(∗)) all the time as compared with carrageenan or carrageenan and PG added low-fat frankfurters. Low-fat frankfurters formulated with either carrageenan or carrageenan with PG had acceptable sensory scores.