Yasemin Sahan

The fungicidal efficacy of various commercial disinfectants used in the food industry

The antifungal effects of eight commercial disinfectants namely alcohol, peracetic acid, iodophors, aldehydes, quaternary amine compounds (QAC, a, b and c), and a chlorine-based agent were assessed at different concentrations. The time taken for these disinfectants to kill different microorganisms was used to assess their efficacy. The microorganisms tested were six yeasts,Saccharomyces cerevisiae, Saccharomyces uvarum, Kloeckera apiculata, Candida oleophila, Metschnikowia fructicola, Schizosaccharomyces pombe, and two moulds,Aspergillus niger (5 strains) andPenicillium roqueforti (5 strains). The disinfectants QAC (a) and QAC (c) were the most effective against all the microorganisms tested. The chlorine-based disinfectant worked most efficiently against the moulds at all concentrations used (0.5, 1.0, 1.5 and 2.0%). Peracetic acid and alcohol based disinfectants were most effective against the yeasts than mould. Tested yeasts were more resistant to the aldehyde and iodophors base disinfectants than the others.

Effect of processing techniques on antioxidative enzyme activities, antioxidant capacity, phenolic compounds, and fatty acids of table olives

In this study, olive fruits (Olea europeae cv. Gemlik) of the most common sources of table olives in Turkey were used. Total polyphenol content (TPC), antioxidant capacity (AC), and antioxidant enzymes (catalase, CAT; ascorbate peroxidase, APX; and glutathione reductase, GR) of table olives were compared by 4 different methods of ripe table olive processing. Results revealed that TPC of the processed olives ranged from 117.44 to 418.69 mg gallic acid equivalents/g fresh weight (f.w.). The highest AC as mg Trolox equivalents of 189.58/g f.w. was obtained from unprocessed black olives. CAT, APX, and GR activities of unprocessed olives were higher than those obtained in all processed olives. In conclusion, TPC, AC, and antioxidant enzyme activities are strongly affected by fruit ripening and processing in table olives of ‘Gemlik’ cultivar. In addition, the best processing technique is untreated black olives in brine for antioxidant properties.

Antifungal activity of olive leaf (Olea Europaea L.) extracts from the Trilye Region of Turkey

Antimicrobial properties of olive leaf extract on some yeast were examined in this study. Fresh olive leaf extracts were prepared using various solvents (water, ethanol, acetone, ethyl acetate) in Soxhlet apparatus. Antimicrobial effects of these extacts were tested againstSaccharomyces cerevisiae ATCC 9763,Schizosaccharomyces pombe, Saccharomyces uvarum, Candida oleophila, Metschnikowia fructicola andKloeckera apiculata. The antifungal activities of these extracts were tested by the disc diffusion assay, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). All extracts showed various degrees of antifungal effects with 10–28 μg/ml MIC, 20–48 μg/ml MFC and 1.5–9.3 mm inhibitory zone values against yeasts utilised, except water. The results indicated that the tested yeasts were sensitive to acetone and ethyl acetate extracts. It was determined thatSaccharomyces cerevisiae ATCC 9763 was the most resistant among the yeasts.

Phenolics, antioxidant capacity and bioaccessibility of chicory varieties (Cichorium spp.) grown in Turkey

In this study, the changes in phenolics, anthocyanin, antioxidant capacity, and bioaccessibility of chicory varieties (Cichorium spp.) in Turkey were investigated. A total of 19 phenolic standards were screened in the chicory varieties studied and the most abundant compounds in the samples, extracted with methanol, were phenolic acids, syringic (2.54mg/kg) and trans-ferulic acid (1.85mg/kg), whilst (+)-catechin was the major flavanol. The highest flavanol content using either methanol or ethanol was determined in the green chicory samples (0.62mg/kg). The red chicory variety had higher anthocyanin (12.80mg/kg), and contained more phenolics, extractable (8855.50mg GAE/100g) and hydrolysable (7005.51mg GAE/100g), than the other varieties. Also, the antioxidant capacities in this variety, as measured using the CUPRAC assay (570.54 and 425.14μmol Trolox/g dw, respectively), had a wider range of difference than was found in the other assays used. Total phenolics were more bioaccessible from the white chicory variety (61.48%). However, the bioaccessibility of antioxidants was higher in the green chicory variety.

Chemical and techno-functional properties of flours from peeled and unpeeled oleaster ( Elaeagnus angustifolia L.)

Oleaster flours were produced from two different genotypes (GO1 and GO2) and methods (peeled oleaster flour: POF and unpeeled oleaster flour: UPOF). Oleaster flour samples (OFs) contained high levels of dietary fibers and micro minerals. The contents of Fe, Cu, B, and Cr in flours obtained from oleaster fruits were higher in UPOF than in POF samples. Palmitic acid was the major fatty acid which was followed by oleic acid and lignoceric acid. All samples contained greater amount of saturated fatty acids (SFA) as compared to mono unsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Among seven different organic acids detected, the level of citric acid was the highest and it was followed by malic, acetic and oxalic acids. High nutritional contents of oleaster flour indicated that it is a good source of dietary fiber, micro minerals, as well as organic and fatty acids. The water solubilities (WS) and water absorption capacities (WAC) of oleaster flours were adequate for their utilization. They also seem to have an improving effect on emulsion properties of albumin. These results highlighted that it is possible to use the oleaster flour in some processed foods such as bakery goods, dairy products (ice cream and yoghurt), beverages and confectionery. Moreover, the oleaster flour could also be used in the preparation of low-fat, high-fiber dietetic products due to its high dietary fiber content.

Some Metals in Table Olives

Publisher Summary Metals in olives are important both from nutritional and toxicological viewpoints. Some metals, particularly iron, copper, and zinc, are essential substances for the human body, and their deficiency can have chronic and acute effects. But even these elements can have toxic effects depending on the chemical form, dose, route of absorption, and a host of other factors. Other metals, especially heavy metals, such as lead and cadmium, are well known as potentially toxic elements. Diseases caused by improper nutrition, including the consumption of food contaminated by trace elements, constitute serious problems in todays world. Heavy metal toxicity can result in damaged or reduced mental and central nervous function, lower energy levels, and damage to blood composition, lungs, kidneys, liver, and other vital organs. Long-term exposure may result in slowly progressing physical, muscular, and neurological degenerative processes that mimic Alzheimers disease, Parkinsons disease, muscular dystrophy, multiple sclerosis and cancer. Metal contamination can take place during the handling and processing of foods, from farm to the point of consumption. Hence, the importance of being able to monitor low-level concentrations of metals in food to ensure that levels are not exceeded. Foods have been analyzed for different elements up to μg kg –1 levels using different techniques such as atomic emission spectrometry (AES), atomic absorption spectrometry (AAS), induced coupled plasma atomic emission (ICP-AES) and induced coupled plasma mass spectrometry (ICP-MS).

Assessing the Bioaccessibilities of Some Elements in Fruit Based Complementary Baby Foods

In this study, total concentrations and bioaccessibility of some essential and toxic elements (As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn) were determined in commercial fruit purees intended for baby consumption as complementary foods. Enzymatic in vitro digestions were performed to simulate the stomach and the intestine conditions. A five-level, three factor central composite design, was applied to optimize the open-wet digestion methodology as well as enzyme amounts used in vitro methods to achieve maximum elemental levels. Rice flour and baby food composite certified reference materials analysis were applied to optimize the digestion parameters and evaluate the accuracy of the optimized method. Water fractions of samples were analyzed and evaluated in terms of their suitability for risk assessment studies by inductively coupled plasma mass spectrometry. Recommended dietary allowance level of 1.3% for Zn, adequate intake levels of 15.3%, 0.04%, 4.4% and 68% for Cu, Mg, Mn and Cr, respectively were achieved as well as 20%, 6% level and 2% tolerable intakes of Cd, Ni and As, respectively. Thus, contribution of the consumption of one jar of fruit based complementary baby food to diet of infants aged up to 12 months were assessed.

Antimicrobial effect of PEG–PLA on food-spoilage microorganisms

Polyethylene glycol (PEG) and polyethylene glycol–polylactic acid (PEG–PLA) have an organic structure and no negative effect on human health. The present study compares the antimicrobial effectiveness of PEG and PEG–PLA on microbial growth. The following pathogens and fungi were examined: seven bacteria strains and 10 fungi (four yeasts and six molds). PEG, a non-modified polymer, exhibited no inhibition effect on all test microorganisms. However, the antimicrobial effect increased with the concentration of PEG–PLA. Bacteria showed more sensitivity to PEG–PLA compared with the other microorganisms used in this study. Enterobacter ATCC 19434 was found to be the most resistant bacteria. Molds and yeasts were more resistant than bacteria against PEG–PLA. MIC and MFC could not be determined on the tested fungi owing to the level of concentrations used, with the exception of the yeast Candida albicans and the molds Penicillium expansum and Aspergillus parasiticus.