Nevzat Artık

Food ellagitannins-occurrence, effects of processing and storage.

Interest in ellagitannins and ellagic acid has increased over the past few years due to its properties as a micronutrient. Ellagitannins are complex plant polyphenols composed of hexahydroxydiphenoyl moieties esterified to a sugar. Fruits (especially berries and nuts) are rich sources of ellagitannins and ellagic acid, a hydrolytic product of ellagitannins. These secondary metabolites give the characteristic taste to the fruits and their products, and also play an important role in food processing. This paper reviews research about occurrence in foods, change during process, and antioxidant activity of ellagitannins and ellagic acid.

Detection of raisin concentrate (Pekmez) adulteration by regression analysis method

Abstract Glucose and fructose as sugar sources were added to raisin concentrate called Pekmez in Turkey at the ratio of 10–25% and 50% w/w, to simulate adulteration in order to develop a statistical regression model. Sugar composition was analyzed with standard enzymatic methods and mineral matters were determined with atomic absorption spectrophotometry. According to the results of analysis for prepared raisin concentrate with different ratios, adulterants could be determined in the limits of variation for each composition component. The minimum variations for these values were fixed and regression models were developed. These statistical models were used in authentication. Regression analysis method could be applied in quality control of raisin concentrate or in monitoring adulteration or contamination.

Rheological and physical properties of Inulin-containing milk chocolate prepared at different process conditions

In the present study, the effects of inulin as a prebiotic substance at various levels (PSL) (0, 60, 90 and 120 g/kg) in milk chocolate, as well as the use of varying conching time (CT) (3.50, 4.0 and 4.50 h) and refining conditions (20.0, 25.0 and 28.0 µm as the mean particle size, D[4,3]) in the sample preparation process were examined with respect to changes in the physical (colour, hardness, water activity) and rheological properties of the samples. Specific surface area (SSA) and largest particle size (D90) values increased with increasing values of PSL; however, intended D[4,3] values were reached for all PSL values. CT, PSL and PSD (particle size distribution) had no significant effect on the brightness and chroma in the inulin-containing milk chocolate; however, it has been found that hardness, water activity, yield stress and viscosity produced significant changes (P < 0.01).

Effect of Storage on 5-Hydroxymethylfurfural (HMF) Formation and Color Change in Jams

In this study, the effects of storage temperature (10, 20, and 37°C) and time (0, 2, 4, and 6 months) on the HMF and color values in strawberry, cherry and apricot jams were studied. Results showed that the HMF and total color difference (ΔE) values of all jams were increased linearly with storage time and higher values were found at higher storage temperature. Kinetic model was applied to changes in HMF and ΔE. Changes in HMF and ΔE were explained using zero-order reaction kinetics and the dependence of the rate constant on temperature was described by the Arrhenius equation

Using polydextrose as a prebiotic substance in milk chocolate: effects of process parameters on physical and rheological properties

Polydextrose, a functional food ingredient, is potentially a prebiotic substance. The rise in diet-related illness has led consumers to take a greater interest in the ingredients of food products. In the present study, in an effort to obtain a prebiotic milk chocolate, the effects of various levels of polydextrose (0, 60, 90 and 120 g/kg) and the use of varying conching times (CT) (3.50, 4.0 and 4.50 h) and refining conditions (20.0, 25.0 and 28.0 µm mean particle size, D[4,3]) in the sample preparation process were examined and analysed with respect to the physical and rheological properties of milk chocolate samples. The use and amount of polydextrose and CT and particle size had statistically significant effects with different magnitudes and directions on the physical and rheological properties of the samples. The samples containing polydextrose significantly differed from the control samples, especially with respect to their rheological properties (p < 0,01).

Microencapsulation of grape polyphenols using maltodextrin and gum arabic as two alternative coating materials: Development and characterization.

Phenolic compounds obtained from fruits have recently gained a great attention due to their bioactive roles. However, they are sensitive and they can be easily affected by physicochemical factors that create a great challenge to incorporate them into the food products. Hence, this work aimed to investigate microencapsulation of these compounds to provide a solution for this problem by improving their stability and protecting them against oxidation, light, moisture and temperature. A lab scale spray-dryer was chosen to produce microcapsules of polyphenols using different dextrose equivalents of maltodextrin and gum arabic as a coating material. Two different core: coating material ratios (1:1 and 1:2), three different maltodextrin: gum arabic ratios (10:0, 8:2 and 6:4), and four different inlet temperatures (120, 140, 160, 180°C) were investigated. When all parameters (yields, hygroscopicity, total and surface phenolic contents, antioxidant activity, individual phenolic compounds and particle morphology) were evaluated; the most efficient microcapsules were obtained with an 8:2 ratio of maltodextrin: gum arabic at 140°C inlet temperature. Microcapsules were also comprehensively studied and characterized using scanning electron microscopy (SEM) and high performance liquid chromatography (HPLC).

Rheological and melting properties of sucrose-free dark chocolate

ABSTRACT In this study, sugar-free dark chocolate was produced from isomalt and maltitol by βV seeding technique as an alternative to conventional tempering process. The effect of βV seed concentrations on the particle size distribution (PSD), textural, rheological and melting properties of the final products were examined and the results were compared with those of conventional sugar-free dark chocolates. For this aim, conched dark chocolates were melted and crystallised with βV seeds which were added at different concentrations (0.5, 0.6, 0.7, 0.8, 0.9 and 1.0%, m/m). According to the results PSD, hardness, rheological and melting properties were not influenced by seeding technique compared to conventional tempering method. On the other hand, inverse relation was observed between largest particle size and specific surface area of the samples. Hardness values of isomalt and maltitol including samples were found to change between 15.33–18.79 N. Casson model best described the flow behaviour of the sugar-free chocolates. As a result, seeding technique can be used as an alternative method in sugar-free dark chocolate production in terms of quality and physical properties.

The Presence of Some Mycotoxins in Corn Grown in Turkey

This study aimed to determine the presence of major mycotoxins of human and animal importance, namely total aflatoxins, fumonisin, deoxynivalenol, zearalenon, T-2 toxin and HT-2 toxin in samples from corn grown in different regions in Turkey. 770 corn samples in total were taken from Çukurova, Sakarya (Adapazarı), Bursa (Karacabey), İzmir (Torbalı), Mersin (Tarsus), Adana (Kozan) ve Şanlıurfa regions between August and November 2015. 625 of the samples were used for total aflatoxin analyses by LC-MS/MS. For other toxin analyses (Fumonisin B1, Fumonisin B2, DON, Zearalenone, T-2 and HT-2) 29 samples were blended for each toxin. The results showed that the highest contamination and risk arises from fumonisin toxins (2652 μg/kg). Mycotoxin contamination in analysed samples was found to be 1.03%. Total aflatoxin was detected as 3.44% (1 of 625), total fumonisin as 17.24% (5 of 29) and zearalenon as 6.89% (2 of 29). None of the samples were found to contain more than one of the analysed mycotoxins. Also, no DON, T-2 or HT-2 toxin was found. In conclusion, the findings of our study on corn produced in Turkey shows that in some regions contamination levels of corn by mycotoxins exceed the legal limits. Supplying contaminated corn and corn products to human and animal consumption may result in serious health problems, moreover it is known that some toxicogenic fungi may cause decrease in quality and yield in