Potential application of natural phenolic antimicrobials and edible film technology against bacterial plant pathogens

The aim of the present study is to use antimicrobial edible film technology and natural phenolic antimicrobials for inhibition of major bacterial plant pathogens such as Erwinia amylovora, Erwinia carotovora, Xanthomonas vesicatoria and Pseudomonas syringae. For this purpose phenolic acids (PAs) (gallic (GA), vanillic (VA), cinnamic acids (CA)), essential oils (EOs) (carvacrol (CAR), thymol (THY), eugenol (EUG) citral (CIT)), phenolic extracts (PEs) from clove (CE), oregano (OE), artichoke stem (ASE) and walnut shells (WSE) were evaluated as antimicrobial zein film components. Films containing PAs between 1 and 4 mg/cm2 inhibited all pathogens while EOs between 1 and 4 mg/cm2 and CE between 4 and 8 mg/cm2 inhibited pathogens except P. syringae. The most potent films were obtained by using GA against E. amylovora and P. syringae, VA against E. carotovora, and CA, THY or CAR against X. vesicatoria. The addition of phenolic compounds into films increased the porosity of films. The phenolic containing films also become more flexible and lost their brittleness. This study is important in that it prepared the basis of using edible antimicrobial coatings in outdoor applications on infected tree stems, soil surfaces and agronomy tools or in classical fruit and seedling coating applications to control bacterial contamination or spoilage

Potential of Turkish Kabuli type chickpea and green and red lentil cultivars as source of soy and animal origin functional protein alternatives

In this study, functional properties of proteins from Turkish Kabuli type chickpea (CPEs) and green and red lentil cultivars (LPEs) were characterized and compared with those of soy and animal proteins. The LPEs and whey protein isolate (WPI) showed higher soluble and total protein content than the other proteins. CPEs showed the highest oil absorption capacity (10.9-14.59 g/g), followed by LPEs (6.90 -10.44 g/g), soy protein extract (8.23 g/g), and egg white proteins (6.37 g/g). The highest water absorption capacities were obtained for bovine gelatin (BGEL) (8.84 g/g), CPEs (4.90-7.94 g/g) and soy protein isolate (7.94 g/g). The foaming capacities of BGEL and fish gelatin (FGEL), and emulsifying capacity of WPI were slightly higher than those of CPEs and LPEs, but most stable emulsions and foams were formed by chickpea and lentil proteins. The least gelling concentration of CPEs (5-7 g/100 g) came second after BGEL (3 g/100 g). The 2-D electrophoresis revealed the detailed isoelectric point (between 4.5 and 5.9) and molecular weight patterns of chickpea and lentil proteins. This study clearly showed that the functional properties of Kabuli chickpea proteins are superior than those of lentil proteins and most of the studied soy and animal proteins.Research Foundation of Izmir Institute of Technolog

Development of antimicrobial protective food coating materials from edible alginate films

Thesis (Master)--Izmir Institute of Technology, Biotechnology, Izmir, 2007Includes bibliographical references (leaves: 92-98)Text in English; Abstract: Turkish and Englishxiv, 101 leavesConsumer interests in high quality, healthy, convenient and safe food continue to increase, presenting food processors with new challenges to which functional edible coating and film concepts offer potential solutions. The interest in the research of edible film which has many advantages and applications has increased during last decade.There is a particular interest in the use of antimicrobial biopreservatives in edible films and to increase food safety without application of chemical preservatives. In this study,we have developed antimicrobial or protective edible films by incorporation of antimicrobial enzyme lactoperoxidase or protective cultures (Lactobacillus delbrueckii subsp. lactis and Lactobacillus plantarum) into alginate films, respectively. The main objective of this research was to increase food safety by using lactoperoxidase or lactic acid bacteria incorporated into alginate films. The results obtained in the study showed that in reaction mixtures, the lactoperoxidase system has antimicrobial activity against E. coli, L. innocua, and P. fluorescens. The developed lactoperoxidase incorporated antimicrobial films also reduced the total microbial load of a selected seafood during cold storage. The lactic acid bacteria, used in edible films for the first time, also successfully incorporated into alginate films. The bacteria showed sufficient stability in alginate films and at surface of red meat during cold storage. The results of this study clearly showed the good potential of using lactoperoxidase and lactic acid bacteria incorporated alginate films in food packaging. The developed films can be used in antimicrobial packaging or protective packaging. However, further studies are needed to show the beneficial effects of developed films on different food systems

A review of current and future food applications of natural hydrocolloids

The main aim of this review paper was to focus on current and potential future sources and food applications of natural hydrocolloids in the food industry. The emerging research trends, problems, new methods and alternative approaches in production, environmental concerns, market trends and newly discovered health benefits have been discussed for natural hydrocolloids of commercial relevance. The rheological and surface active properties, interactions, functional properties, films and coatings, encapsulation applications and nanotechnology uses of natural hydrocolloids have been discussed in the light of recent developments. This review also reflected the most up-to-date concepts of applying natural hydrocolloids to meet consumer's and food sector's sophisticated demands related to food products

Production of B-galactosidase using lactic acid bacteria and optimisation of fermentation parametters

Thesis (Master)--Izmir Institute of Technology, Biotechnology, Izmir, 2007Includes bibliographical references (leaves: 90-97)Text in English; Abstract: Turkish and Englishxiii, 120 leavesFood grade thermostable B -galactosidase preparations are always in demand for a number of industrial applications. Thermostable -galactosidases from LAB having a neutral pH-optimum can be safely used to reduce the lactose content of milk for the lactose intolerant people. In this study, -galactosidase was produced with high productivities by novel Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains isolated from traditional Turkish yogurt samples in Toros mountain region. A full factorial statistical design was used separately for Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains in screening experiments. Among the strains, Lactobacillus delbrueckii subsp. bulgaricus 77 and Streptococcus thermophilus 95/2 were found to have high potential for B-galactosidase and lactic acid production, therefore these were used in the further optimisation studies.The efficiency of different cell disruption methods was investigated on the extraction of -galactosidase. Among these, lysozyme enzyme treatment was determined as the most effective method. Optimisation studies were carried out using response surface methodology to optimize fermentation conditions for pure strains as well as for mixed ones. Therefore, symbiotic relationship between St 95/2 and Lb 77 were investigated as well. Symbiotic relationship provided 39% and 6.1 % more -galactosidase activity and 44 % and 9.73 % more lactic acid production when compared to the optimisation results of pure strains Lb 77 and St 95/2, respectively.Overall, characterization studies showed that enzymes obtained from these strains can be considered as food grade and thermostable since they are obtained from thermophile, food originated novel LAB of local microflora

Bioactive, functional and edible film-forming properties of isolated hazelnut (Corylus avellana L.) meal proteins

This study aimed characterization of bioactive, functional and edible film making properties of isolated proteins from untreated (HPI), hot extracted (HPI-H), acetone washed (HPI-AW), and acetone washed and hot extracted (HPC-AW-H) hazelnut meals. The most bioactive protein extract was HPC-AW-H, followed by HPI-AW, HPI-H and HPI, based on antioxidant activity (TEAC and ORAC: 158-461mmolTrolox/kg), iron chelation (60.7-126.7mmolEDTA/kg), angiotensin-converting enzyme inhibition (IC50: 0.57-1.0mg/mL) and antiproliferative activity on colon cancer cells (IC50: 3.0-4.6mg/ml). Protein contents of HPI, HPI-H and HPI-AW (93.3-94.5%) were higher than that of HPC-AW-H (86.0%), but HPC-AW-H showed the best pH-solubility profile. The extracts showed good oil absorption (7.4-9.4g/g) and foaming, but limited water holding and gelling capacities, and emulsion stability. The protein extracts gave transparent, yellowish to brownish and reddish colored and water soluble edible films. The HPI gave the lightest colored films with acceptable mechanical properties (elongation up to 144% and tensile strength up to 4.9MPa). 1-D and 2-D electrophoresis clearly showed the molecular and isoelectric profiles of hazelnut proteins. The overall results of this study showed that the bioactive, solubility and gelation properties of hazelnut proteins could be improved by simple processes like acetone washing and/or heat treatment. The hazelnut proteins are valuable as multipurpose food ingredients.Foundation of Izmir Institute of Technology (IZTECH

Lead pollution and its sources along the Turkish coast of the Black Sea

Lead pollution and its sources have been investigated in the south-eastern and south-western Black Sea. Surficial sediments and mussels were collected in different seasons of the year from the south-eastern and south-western Black Sea and analysed for their lead contents.In the south-eastern Black Sea sediments from the easternmost and from the central stations contained the highest lead concentrations. Sediments contained 8 to 10 times the lead concentrations of sediments from the south-west. Samples taken from rivers, streams and effluents had especially high lead concentrations. The highest lead concentrations were found in sediments collected in October and December.Lead concentrations in mussels from the south-eastern coast were comparatively lower compared to those from the south-western coast. The highest average values occurred in December and in October.In the south-western Black Sea, the highest lead concentrations in sediments were obtained in those from Inebolu, followed by those from around Zonguldak. The concentrations increased from the middle to the west of the southern Black Sea coast, possibly due to the effect of the Danube River. Sediments taken in September had the highest lead concentrations, followed by samples taken in December.Very high lead concentrations (> 10 μ g g-1) were observed in mussels from those stations where the sediments also contained high concentrations. Mussels had their highest lead concentrations in January and April

Chitosan/Modified Banana Epidermis Starch Composite Films for Food Packaging Applications

Banana epidermis is a waste material and starchier, it can be used to made biodegradable composite film and their properties were characterized. The aim of this study was to develop biodegradable composite films based on modified banana epidermis starch. The role of modified banana epidermis starch (MBES) particle loadings were analyzed on chitosan semi-crystalline structure, in addition to studying the composite film properties such as barrier, thermal and mechanical properties. Antimicrobial activity of the composite films is developed based on chitosan and MBES particle. The composite films are produced by solution casting method. The composites exhibit a significantly good in the mechanical and thermal stability. The resulting Chitosan/MBES films exhibit better oxygen permeation rate while compared with normal commercial films. The new prepared composite films have a high potential, mechanical, morphological, antimicrobial activity, and to improve their long-lasting antimicrobial efficiency for food packaging applications

Characterization and genetic mapping of health related traits in tomato

Thesis(Master)--İzmir Institute of Technology, Biology, İzmir, 2005Includes bibliographical referencesText in English; Abstract: Turkish and Englishix, 51 leavesTomato is consumed in the daily diet and has a diverse nutritional content including antioxidants, lycopene, vitamin C and phenolics. However, the content of these compounds in tomato cultivars could be higher. There are two ways of increasing the nutritional quality of tomato. One of them is a transgenic way which is still questioned and is not approved in many countries. The other way is molecular breeding which is based on introgression of wild genes into cultivated tomatoes via the combination of classical breeding with molecular marker analysis. This method lets us obtain nontransgenic tomatoes with increased nutritional quality. In this project a population that was obtained from a cross between wild type L.pimpinellifolium and cultivated tomato L.esculentum was used. This population includes 145 inbred backcross lines (IBLs). It was expected that some individuals of this population had increased nutritional quality derived from the wild parent. In order to test this hypothesis, antioxidant activity of each line was measured. The method used to measure antioxidant activity was based on spectrophotometric measurement which gave mol Trolox equivalent antioxidant activity. It was observed that the IBLs were phenotypically close to L.esculentum and that some individuals did have higher antioxidant activity than the cultivated parent. The population was also mapped with molecular markers and 31 possible QTLs which control antioxidants in tomato were found. The source of alleles associated with increased antioxidant characters was usually L.pimpinellifolium. This result confirmed that wild type tomatoes can be a resource for increasing nutritional quality of tomatoes

Translational regulation contributes to the elevated CO2 response in two Solanum species.

Understanding the impact of elevated CO2 (eCO2 ) in global agriculture is important given climate change projections. Breeding climate-resilient crops depends on genetic variation within naturally varying populations. The effect of genetic variation in response to eCO2 is poorly understood, especially in crop species. We describe the different ways in which Solanum lycopersicum and its wild relative S. pennellii respond to eCO2 , from cell anatomy, to the transcriptome, and metabolome. We further validate the importance of translational regulation as a potential mechanism for plants to adaptively respond to rising levels of atmospheric CO2