Soil productivity analysis based on a fuzzy logic system

BACKGROUND: Maintaining soil productivity is essential if agriculture production systems are to be sustainable. However, there is a paucity of tools for measurement for the purpose of understanding changes in soil productivity. Fuzzy logic‐based analysis offers this possibility. It is a new method on the evaluation of soil productivity in Turkey and even in the world. RESULTS: Values for pH, salinity, carbonate and organic matter were entered into the system as input variables so as to obtain soil productivity as the output. After the membership functions related to input and output were determined, rules were created. Then, the fuzzy logic system was applied separately to pH, salinity, lime and organic matter values of different soil types present in the Kocaeli region with the aim of obtaining corresponding fuzzy values. Thus, soil productivity profiles of the region were deciphered. CONCLUSION: Organic matter levels in the study field remained below 30 g kg^?1 and varied between 22 and 28 g kg^?1. Productivity values were obtained as a percentage and varied between 16.9% and 18.1%. The lime content of the study soils varied in the range of 33–88 g kg^?1. Average totals for salt values of the field changed between 0.58 and 0.77 g kg^?1. Copyright © 2010 Society of Chemical Industry     

Constraints in meeting food safety and quality requirements in the Turkish dairy industry: a case study of Izmir province

Recent global developments concerning food quality and food safety have influenced and stimulated food legislation in Turkey in accordance with internal and international trade and agreements. In this study, the way in which the dairy industry conforms to this legislation was analyzed through a case study of Izmir province, which generally has all the structural characteristics of the dairy sector in Turkey. A survey in which dairy plant managers responded to a special questionnaire was used to collect data from 86 dairy plants chosen on the basis of proportional sampling. According to the results of this study, (i) there are many dairy processors in the region, (ii) most managers have a limited education concerning their positions, (iii) most firms handle small volumes of milk and have little control over the raw milk supply, (iv) resources are too limited in these firms, limiting their ability to adopt most regulations, and (v) few processors apply the regulatory practices imposed by governmental agencies. Thus, food legislation is not enough to ensure food safety in the dairy industry in Turkey. Technical and educational support should be given to farmers and the staff of dairy firms by the Ministry of Agriculture to form an appropriate food safety infrastructure in Turkey for the milk and processed dairy products industry.     

Volatile compounds of olive oils from different geographic regions in Turkey

In this research, changes in volatile compounds of olive oil were investigated in terms of cultivar, harvest year, and geographic regions (Mediterranean, Aegean, Southeastern Anatolia, Marmara, and Black Sea) were investigated. Volatile compounds of olive oils were extracted by using solid-phase microextraction (SPME) method and were identified with gas chromatography–mass spectrometry. A total of 59 volatile compounds from seven different chemical groups including aldehydes, ketones, hydrocarbons, alcohols, esters, terpenes, and furans were identified. Aldehydes were detected as the major group in all geographic regions. Among aldehydes, trans-2-hexenal was found to be relatively higher. Alcohols and esters were determined as other important compounds. While many volatile compounds were affected by olive cultivar factor, this factor had no significant effect on esters. Principal component analysis showed that volatile compounds could play an important role in the separation of regions.     

Interactions between milk proteins and polyphenols: Binding mechanisms,related changes,and the future trends in the dairy industry

The biological activity and techno-functional properties of phenolic compounds have gained great importance due to the epidemiologically-proved health benefits. Use of polyphenols as fortification agents for functional food production and nanotechnological approaches using natural vehicles for polyphenol delivery have been recently discussed. In this respect, milk proteins and dairy products represent unique characteristics for polyphenol studies. The conflicting results on the functionality of polyphenols interacting with milk proteins either in model systems or in complex dairy matrices reveal the need for future studies.     

Effect of high hydrostatic pressure on physicochemical and biochemical properties of milk

Interest in high hydrostatic pressure (HHP) applications on milk and dairy products has recently increased as HHP offers a new technology for food preservation to the food industry. Although HHP-induced microbial destruction, rennet or acid coagulation of milk and increase in cheese yield has been reported, the actual effect of HHP application on milk constituents still remains to be unexplained. Therefore, we have analyzed the effect of HHP on physicochemical and biochemical properties such as turbidity, pH and especially protein micelle surface hydrophobicity of milk proteins. To serve for this purpose, milk samples with different fat contents were pressurized from 110 to 440 MPa at 25 °C for 10 and 20 min. Turbidity decreased with pressure increase and there was a slight change in pH. In order to measure the extent of exposure of hydrophobic groups of proteins to HHP, the method described by Bonomi et al. [1], based on use of a fluorescent probe, was utilized. In the light of the results obtained, it can be concluded that HHP has an effect on non-covalent interactions and especially hydrophobic bonds in milk. As the pressure is increased from 110 to 440 MPa, the micelles possibly decompose into sub-micelles and the embedded hydrophobic areas inside these micelles re-position in such a way that they can readily interfere with the fluorescent marker, ANS. These results may lead to practical applications of HHP treatment in the dairy industry to produce microbiologically safe, minimally processed products with high nutritional and sensory quality and novel texture.     

Strategies to prevent mycotoxin contamination of food and animal feed: a review

Mycotoxins are fungal secondary metabolites that have been associated with severe toxic effects to vertebrates produced by many important phytopathogenic and food spoilage fungi including Aspergillus, Penicillium, Fusarium, and Alternaria species. The contamination of foods and animal feeds with mycotoxins is a worldwide problem. We reviewed various control strategies to prevent the growth of mycotoxigenic fungi as well as to inhibit mycotoxin biosynthesis including pre-harvest (resistance varieties, field management and the use of biological and chemical agents), harvest management, and post-harvest (improving of drying and storage conditions, the use of natural and chemical agents, and irradiation) applications. While much work in this area has been performed on the most economically important mycotoxins, aflatoxin B(1) and ochratoxin A much less information is available on other mycotoxins such as trichothecenes, fumonisin B(1), zearalenone, citrinin, and patulin. In addition, physical, chemical, and biological detoxification methods used to prevent exposure to the toxic and carcinogenic effect of mycotoxins are discussed. Finally, dietary strategies, which are one of the most recent approaches to counteract the mycotoxin problem with special emphasis on in vivo and in vitro efficacy of several of binding agents (activated carbons, hydrated sodium calcium aluminosilicate, bentonite, zeolites, and lactic acid bacteria) have also been reviewed.     

Effect of vanillin, ethyl vanillin, and vanillic acid on the growth and heat resistance of Cronobacter species

Preservatives could be part of an effective intervention strategy for the control of Cronobacter species in foods, but few compounds with the desired antimicrobial properties have been identified to date. We examined the antibacterial activity of vanillin, ethyl vanillin, and vanillic acid against seven Cronobacter spp. in quarter-strength tryptic soy broth with 5 g/liter yeast extract (TSBYE) adjusted to pH 5.0, 6.0, and 7.0 at 10, 21, and 37°C. All compounds exhibited pH- and temperature-dependant bacteriostatic and bactericidal activity. MICs of vanillin and ethyl vanillin consistently increased with decreasing pH and temperature, but vanillic acid had little activity at pH values of 6.0 and 7.0. The MICs for all temperatures, pH values, and bacterial strains tested were 2 mg/ml ethyl vanillin, 3 mg/ml vanillin, and >8 mg/ml vanillic acid. MBCs also were influenced by pH, although significantly higher concentrations were needed to inactivate the bacteria at 21°C than at 10 or 37°C. Survivor curves for Cronobacter sakazakii strains at the MBCs of each compound revealed that all treatments resulted in immediate loss of cell viability at 37°C. Measurements of propidium iodide uptake indicated that the cell membranes were damaged by exposure to all three compounds. The thermal resistance of C. sakazakii was examined at 58°C in TSBYE supplemented with MBCs of each compound at pH 5.0 and 6.0. D-values at pH 5.0 were reduced from 14.56 ± 0.60 min to 0.93 ± 0.01, 0.63 ± 0.01, and 0.98 ± 0.02 min for vanillin, ethyl vanillin, and vanillic acid, respectively. These results suggest that vanillin, ethyl vanillin, and vanillic acid may be useful for the control of Cronobacter spp. in food during preparation and storage.