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Salinity is one of the most important factors restricting vegetative production, especially in arid and semi-arid regions. In this study,the effects of the exogenous plant growth-promoting rhizobacteria (PGPR: Bacillus pumilus UG-41, Bacillus cereus UG-50) application on seedling growth, concentration of plant nutrient elements, antioxidant activity and chlorophyll, proline, sugar, hydrogen peroxide (H2O2), malondialdehyde (MDA), hormone contents of pepper seedlings under salinity stress conditions (100 mM NaCl) were investigated. Our results showed that gibberellic acid (GA), salicylic acid (SA), indole acetic acid (IAA), leaf relative water content (LRWC) and the concentration of all plant tissue nutrients investigated except for Na were decreased by salt stress. On the other hand, PGPR treatment increased the plant growth parameters by increasing the proline, sucrose, hormone and chlorophyll contents; altering the mineral uptake and increasing the antioxidant enzyme activity in pepper seedlings under salt stress. In conclusion, PGPR treatment may be used as an effective technique to protect the plants against salinity stress since the bacteria positively impact the ability of the plant to cope with the stress by particularly increasing the antioxidant enzyme activity, hormone level and mineral uptake.

Plant biostimulants are microorganisms (PGPR) and/or products obtained from different organic substances that positively affect plant growth and efficiency and reduce the negative effects of abiotic challenges. Effects of biostimulants on the plant growth, yield, mineral content, antioxidant enzyme activity, H2O2, malondialdehyde (MDA), sucrose, and proline contents of cherry tomato (Solanum lycopersicum var. cerasiforme L.) grown in soils with two different characteristics were investigated during a pot study under greenhouse conditions. Soil I was a fertile routinely vegetable-cultivated soil. Soil II had high salinity, high CaCO3 content, and low organic matter content. Commercial biostimulant products Powhumus® (PH), Huminbio Microsense Seed® (SC), Huminbio Microsense Bio® (RE), and Fulvagra® (FU) were used as seed coatings and/or drench solutions. All biostimulant treatments improved the plant growth and yield compared with the control in both soils. All biostimulant applications were more effective in soil II than in soil I. RE was the most effective application for mineral content in soil I, whereas FU was the most effective in soil II. Antioxidant activity, H2O2, MDA, and proline contents were decreased in both soils when biostimulants were used compared with the control. Peroxide (POD) activity was greater with SC1 in soil II. The RE treatment increased the sucrose content in soil II. In conclusion, single and combined use of high-purity fulvic acid and PGPR had positive effects on the growth of cherry tomato in fertile soil and under stressed conditions.

Intercropping systems are one of the sustainable agricultural models as they play an important role in protecting soil fertility, efficient use of resources, maintaining stable yields, and reducing the effectiveness of diseases and pests. The aim of this study was to investigate the effects of intercropping (IC) cauliflower (Brassica oleracea L. var. botrytis) with leaf lettuce (Lactuca sativa L. var. crispa) on the yield and quality parameters of cauliflower and to evaluate the overall productivity of the system under different nitrogen fertilization rates (160, 200, and 240 kg N ha−1). Our results showed that the leaf chlorophyll value (SPAD), plant weight, leaf weight, head diameter, head height, head weight, and total yield of cauliflower were found to increase as the nitrogen dose increased in both the monocropping (MC) and IC systems. The most efficient nitrogen fertilizer doses for cauliflower were 234.7 kg ha−1 for MC and 176.6 kg ha−1 for IC, respectively. When the intercropping system was used the total yield (cauliflower and lettuce) was higher than the yield of cauliflower (MC) for the same total area and fertilizer amount. The land equivalent ratio (LER) values were greater than 1 in the intercropping system at all fertilization rates, which indicated that the IC system was more productive than the MC system for the same unit of land. Our findings also showed that intercropping was an effective method to increase fertilizer use efficiency and the soil organic matter, nitrogen content, plant available P, K, Mg, Zn, Fe, Mn, and Cu. In conclusion, while intercropping cauliflower with lettuce did not adversely affect the yield of cauliflower, it enabled harvesting more plants (cauliflower and lettuce) from the same land area by using the same amount of fertilizer, which makes intercropping a sustainable, economical, and ecological model that increases the land-use and fertilizer-use efficiencies.

As a consequence of development and industrialization, the excessive use of toxic organic and inorganic chemicals as well as heavy metals, has caused an uncontrolled accumulation of chemical waste in soil, water and air. Today, it has become a global issue since all living things suffer as a result of direct or indirect exposure to these chemicals. Bioremediation is a sustainable and economical solution to this environmental problem, where microorganisms in the ecosystem are used to convert and/or degrade and/or remove pollutants. This chapter summarizes the role of plant growth-promoting rhizbacteria as biological control agents in the biosorption of soil contaminants, including heavy metals and organic compounds. The bioremediation approaches are explained and research findings are discussed to serve as a guide for those interested in this subject.

Soil microorganisms perform a variety of functions, some of which are extremely helpful to the maintenance of ecological sustainability. Bacteria thriving in the plant rhizosphere drive plant development through a variety of ways, which are referred to as PGPRs (plant growth-promoting rhizobacteria). Despite the fact that there are many different types of PGPRs, their significance and applications in sustainable agriculture are still debated and limited. The performance of PGPRs vary, which might be related to a variety of environmental conditions that impact their development and proliferation in plants. PGPR is a nonpathogenic, friendly bacterium that stimulates plant development by altering hormone concentrations and nutritional needs, as well as mitigating stress-related damage. PGPRs colonize root hairs and lateral roots in plants, where they may exhibit their beneficial characteristics. Rhizobacteria that promote plant development have the ability to control root system architecture (RSA), as well as the vegetative growth and physiology of the entire plant. The generation of hormones like Indole acetic acid (IAA) by PGPR has long been linked to RSA effects. This book chapter reviews the effects of PGPRs on the growth, the physiological, biochemical, and molecular characteristics of plant roots as well as the mechanisms involved.

The aim of this study is to understand Turkish consumers‘ perception of functional dairy products in three different categories, namely milk, yogurt, and cream cheese, as well as their willingness to buy products with health claims. In this study, 50 untrained participants from the city of İstanbul, Turkey, were enrolled to evaluate three types of milk (calcium & vitamin fortified, soy, and whole), three types of yogurt (probiotic, strawberry flavoured probiotic, and plain) and four types of cream cheese (calcium, phosphate & vitamin fortified, reduced fat, light, and regular) using free listing testing and check-all-that-apply (CATA) questions together with Yes/No questions. Twenty-five participants were recruited from Yeditepe University‘s Food Engineering Department and 25 participants from public places to form two clusters. In the free listing analysis, the number of frequent terms related to health dramatically decreased after the tasting session for all products, whereas sensory related terms became more important. CATA analysis showed that consumers look for different product properties in different dairy categories. The findings of both analyses showed that, regardless of their education and awareness, consumers still are not willing to compromise on the taste of dairy foods independent of how healthy the product might be. Their preference of functional dairy products was only 22%, 26% and 14% for fortified milk, probiotic yogurt, and fortified cream cheese, respectively. Moreover, only 30% of the participants were found to believe the health claims on the package, which is another obstacle the functional food industry has to face.

Ülkemizde mısır üretimindeki artış bir yandan sürerken, bir yandan da dünyada mısırın soyadan sonra en çok genetiği değiştirilmiş ürün olması nedeniyle tüketicinin mısır ile ilgili algısı her geçen gün daha olumsuz olmaktadır. Genetiği değiştirilmiş mısırın potansiyel olumsuz etkileri tartışılmakta iken, mısırda insan sağlığı için gözden kaçmaması gereken en büyük tehdit mikotoksinlerdir. Bu çalışmada, Türkiye‘nin 24 ilinde bulunan 552 köyün 634 tarlasından toplanan mısır numuneleri GDO, aflatoksin B1, toplam aflatoksin, fumonisin B1, fumonisin B2, T-2 toksin, HT-2 toksin, zearalenon ve deoksinivalenol yönünden incelenmiştir. Tarama yapılan mısır numunelerinin hiçbirinde transgenik elemente rastlanmamıştır. Analiz edilen 634 numunenin sadece bir tanesinde Türk Gıda Kodeksi limitinin üzerinde aflatoksin B1 miktarına rastlanmış, numunelerin toplam aflatoksin değerleri Türk Gıda Kodeksi limitinin altında çıkmıştır. Paçal oluşturulan numunelerin hiçbirinde T-2 toksin, HT-2 toksin, zearalenon ve deoksinivalenol tespit edilmezken, fumonisin tespit edilen numunelerin toplam fumonisin miktarı Türk Gıda Kodeksi limitinin altında bulunmuştur. Bu sonuçlar, yerli üretim mısırların gıda güvenliği açısından uygun standartları sağladığını göstermektedir.

Cadmium (Cd) is a toxic and very mobile heavy metal that can be adsorbed and uptaken by plants in large quantities without any visible sign. Therefore, stabilization of Cd before uptake is crucial to the conservation of biodiversity and food safety. Owing to the high number of carboxyl and phenolic hydroxyl groups in their structure, humic substances form strong bonds with heavy metals which makes them perfect stabilizing agents. The aim of this study was to determine the effects of humic and fulvic acid (HA + FA) levels (0, 3500, 5250, and 7000 mg/L) on alleviation of Cadmium (Cd) toxicity in garden cress (Lepidium sativum) contaminated with Cd (CdSO4.8H2O) (0, 100, and 200 Cd mg/kg) under greenhouse conditions. Our results showed that, Cd stress had a negative effect on the growth of garden cress, decreased leaf fresh, leaf dry, root fresh and root dry weights, leaf relative water content (LRWC), and mineral content except for Cd, and increased the membrane permeability (MP) and enzyme (CAT, SOD and POD) activity. However, the HA + FA applications decreased the adverse effects of the Cd pollution. At 200 mg/kg Cd pollution, HA + FA application at a concentration of 7000 mg/L increased the leaf fresh, leaf dry, root fresh, root dry weights, stem diameter, leaf area, chlorophyll reading value (CRV), MP, and LRWC values by 262%, 137%, 550%,133%, 92%, 104%, 34%, 537%, and 32% respectively, compared to the control. Although the highest H2O2, MDA, proline and sucrose values were obtained at 200 mg/L Cd pollution, HA + FA application at a concentration of 7000 mg/L successfully alleviated the deleterious effects of Cd stress by decreasing H2O2, MDA, proline, and sucrose values by 66%, 68%, 70%, and 56%, respectively at 200 mg/kg Cd pollution level. HA + FA application at a concentration of 7000 mg/L successfully mitigated the negative impacts of Cd pollution by enhanced N, P, K, Ca, Mg, Fe, Mn, Cu, Mn, Zn, and B by 75%, 23%, 84%, 87%, 40%, 85%, 143%, 1%, 65%, and 115%, respectively. In addition, HA + FA application at a concentration of 7000 mg/L successfully reduced Cd uptake by 95% and Cl uptake by 80%. Considering the plant growth parameters, the best results were determined when HA + FA concentration was 7000 mg/L. We have shown that, it is critical to apply a humic substance with high percentage of FA, which was 10% in this study, to mitigate the adverse effects of heavy metal stress on plant growth. In conclusion, the application of HA + FA may be suggested as an effective solution for reducing the Cd uptake of the plants by stabilizing Cd in soil and preventing translocation of Cd from the roots of plant to its shoot and leaves.

Ethnopharmacological relevance Okra fruit (Abelmoschus esculentus (L.) Moench) has been extensively used for the treatment of skin damage and subcutaneous tissue abscess for many years in Turkish folk medicine. Aim of study In this study, we aimed to investigate the wound healing potential of okra fruit by in vitro and in vivo experimental models in detail. Furthermore, based on the results of experiments, a wound healing formulation was developed and its activity profile was studied. Materials and methods For this purpose, the phenolic, flavonoid and proanthocyanidin contents and chemical profile of aqueous and ethanolic extracts prepared from okra fruits cultivated in two different locations of Turkey, i.e. Aegean and Kilis regions, were comparatively determined and the tryptophan levels, which is known to be an influential factor in wound healing, were measured. Antioxidant activity of the okra fruit extracts was determined by DPPH test, ABTS radical scavenger activity, iron-binding capacity, total antioxidant capacity and copper reduction capacity assays. Moreover, antibacterial activity potentials of the aqueous and ethanolic extracts of okra fruits were determined. The protective effect of the extracts against H2O2-induced oxidative stress and anti-inflammatory activity were assessed in HDF (human dermal fibroblast) cells and in RAW 264.7 murine macrophages, respectively. The biocompatibility of the gel formulations prepared with the best performing extract were evaluated by human Epiderm™ reconstituted skin irritation test model. Wound-healing activity was investigated in rats by in vivo excision model and, histopathological examination of tissues and gene expression levels of inflammation markers were also determined. Results According to our findings, the aqueous and ethanolic extracts of okra fruits were found to possess a rich in phenolic content. Besides, isoquercitrin was found to be a marker component in ethanolic extracts of okra fruits. Both extracts exhibited antioxidant activity with significant protective effect against H2O2-induced damage in HDF cells by diminishing the MDA level. Also, the highest dose of ethanolic extracts has displayed a potent anti-inflammatory activity on LPS-induced RAW264.7 cells. Besides, both water and ethanolic extracts were shown to possess antimicrobial activity. On the other hand, the formulations prepared from the extracts were found non-irritant on in vitro Epiderm™ -SIT. In vivo excision assay showed that tissue TGF-β and IL-1β levels were significantly decreased by the 5% okra ethanolic gel formulation. The histopathological analysis also demonstrated that collagenisation and granulation tissue maturation were found higher in 5% (w/v) okra ethanolic extract-treated group. Conclusion 5% of okra ethanolic extract might be suggested as a potent wound healing agent based on the antimicrobial, antioxidant and anti-inflammatory tests. The proposed activity was also confirmed by the histopathological findings and gene expression analysis.

Pectin was first dissolved in distilled water and blended with low contents of polyethylene oxide 2000 (PEO2000) as the carrier polymer to produce electrospun fibers. The electrospinning of the water solution of pectin at 9.5 wt% containing 0.5 wt% PEO2000 was selected as it successfully resulted in continuous and non-defected ultrathin fibers with the highest pectin content. However, annealing of the resultant pectin-based fibers, tested at different conditions, developed films with low mechanical integrity, high porosity, and also dark color due to their poor thermal stability. Then, to improve the film-forming process of the electrospun mats, two plasticizers, namely glycerol and polyethylene glycol 900 (PEG900), were added to the selected pectin solution in the 2–3 wt% range. The optimal annealing conditions were found at 150 °C with a pressure of 12 kN load for 1 min when applied to the electrospun pectin mats containing 5 wt% PEO2000 and 30 wt% glycerol and washed previously with dichloromethane. This process led to completely homogenous films with low porosity and high transparency due to a phenomenon of fibers coalescence. Finally, the selected electrospun pectin-based film was applied as an interlayer between two external layers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by the electrospinning coating technology and the whole structure was annealed to produce a fully bio-based and biodegradable multilayer film with enhanced barrier performance to water vapor and limonene., This study was supported by the Turkish Scientific and Technological Research Council (TUBITAK) 2214-A International Research Fellowship Programme for PhD Students and by the Spanish Ministry of Science, Innovation, and Universities (MICIU) project numbers AGL2015-63855-C2-1-R. S.T.-G. is a recipient of a Juan de la Cierva—Incorporación contract (IJCI-2016-29675) from MICIU.

Food packaging technology has been advancing to provide safe and high quality food products and to minimize food waste. Moreover, there is a dire need to replace plastic materials in order to reduce environmental pollution. The aim of this study was to prepare biodegradable antimicrobial packaging films from gelatin. Boric acid, disodium octaborate tetrahydrate, and sodium pentaborate were incorporated as the antimicrobial agents. Films containing boric acid and its salts showed antibacterial effect against Staphylococcus aureus and Pseudomonas aeruginosa, as well as antifungal and anticandidal effects against Aspergillus niger and Candida albicans. The mechanical strength of the films was mostly enhanced by the addition of boron derivatives. The rheological measurements and Fourier-transform infrared spectroscopy results suggest that boron derivatives did not interfere with the network formation during gelling. The morphology of boron-added antimicrobial films was found to be similar to the morphology of the control. In conclusion, the newly developed gelatin films containing 10% or 15% disodium octaborate (g/g gelatin) might be good candidates for biodegradable antimicrobial packaging materials. © TÜBİTAK.

Xanthan gum and chitosan can form physically crosslinked hydrogels of high swelling capacity. Xanthan-chitosan polyelectrolyte complex gels have been studied as microcarriers mostly for the encapsulation of enzymes while the studies on the applicability of the system for bacterial cells are scarce. In this work, probiotic bacteria were encapsulated in xanthan-chitosan gels. The main goal of this study was to characterize the swelling and the release behaviors of xanthan-chitosan hydrogel system under simulated GI-tract conditions to be able to assess its potential as an enteric delivery system for probiotics. We found that the cell release in simulated gastric fluid (SGF) at pH 2.0 for 2 h was negligible, and the complete release of the cells from the capsules in simulated intestinal fluid (SIF) was achieved in 5 h. The pH of the SGF solution was found to be more critical in determining the release properties of the capsules than the presence of the enzyme. The cell release kinetics under GI-tract conditions was also characterized. Cell release from xanthan-chitosan capsules in SIF (after 2 h exposure to SGF at pH 2.0), exhibited a Super Case II transport mechanism regardless of the formulation used, meaning that the chain relaxation is the driving mechanism for the release. Moreover, xanthan-chitosan capsules were found to swell by a diffusion-controlled mechanism. Additionally, cell viability study showed that xanthan-chitosan encapsulation provides a good protection for the probiotics. These results may suggest that xanthan-chitosan capsules have a good potential for the delivery of the probiotics to the intestines. (C) 2014 Elsevier Ltd. All rights reserved.

Characterizing the parameters critical to the prediction of a successful electrospinning process from solution properties is essential, yet, not easy in the case of biopolymers. In this study, we attempted to present a broad perspective by simultaneously evaluating the effect of eight different parameters, namely zero shear viscosity, tip viscosity, elastic modulus, phase angle, cohesive energy, pH, conductivity, and surface tension, on the formation of smooth pectin nanofibers. Our results showed that (1) the viscosity of the solution is not an indication of jet formation, but once the jet is formed, high zero shear viscosity and high tip viscosity are required to maintain a dominant whipping instability for smooth nanofiber formation and (2) while evaluating the elasticity of the spinning solutions, comparing only the elastic modulus values would be misleading, since low phase angle values are also necessary for pectin solutions to be electrospun into nonbeaded fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48294. © 2019 Wiley Periodicals, Inc. Istanbul Teknik Üniversitesi We would like to thank Assoc. Prof. Filiz Altay from Istanbul Technical University for the use of tensiometer for surface tension measurements and to AROMSA Inc. (Kocaeli, Turkey) for kindly providing the pectin for this study. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conformational changes of xanthan gum as a function of concentration were investigated to elucidate its unusual flux behavior during ultrafiltration (UF). The contribution of hydrogen bonding on structure formation and the molecular orientation of xanthan gum on the flow characteristics were studied rheomechanically and rheo-optically. Known to affect xanthan structure at low concentrations, hydrogen bonding unexpectedly did not show significant influence on xanthan rheological properties up to 2 wt %. The ordered layers formed on the membrane surface proved responsible for the enhanced water removal during UF. This unique behavior could be attributed to the formation of aligned molecular orientation in addition to the viscosity increases during the biphasic region. Significant differences were observed between xanthan fermentation broth and solutions made of commercial xanthan, suggesting the need to control the salt concentration in fermentation broth in order to make UF an effective recovery process for xanthan gum after fermentation. PRACTICAL APPLICATIONS The knowledge gained from the present study strengthens fundamental understandings on the conformational changes of xanthan biopolymers during the recovery of xanthan gum from fermentation broth using ultrafiltration (UF). By taking advantage of the aligned molecular orientation, along with controlling the salt concentration in the fermentation broth, UF could be operated at elevated flux to speed up the removal of water from the viscous fermentation broth. The technology should find broad applications in the fermentation industry, especially where viscosity is of concern during the separation and purification of the product.

Polyelectrolyte hydrogels formed by xanthan gum and chitosan can be used for encapsulation and controlled release of food ingredients, cells, enzymes, and therapeutic agents. In this study, xanthan-chitosan microcapsules were formed by complex coacervation. The effects of initial polymer concentration and chitosan solution pH on the crosslinking density of xanthan-chitosan network were investigated by swelling studies and modulated differential scanning calorimetry (MDSC) analysis. The crosslinking density was found to be less dependent on chitosan solution concentration than xanthan solution concentration and chitosan pH. The capsules were completely crosslinked at all conditions studied when initial xanthan solution concentration was 1.5%(w/v). The changes in the conformation of chitosan chains as chitosan pH approaches 6.2 were found to be important in achieving capsule network structures with different crosslinking densities. These findings indicate that the parameters studied cannot be viewed as independent parameters, as their effects on the degree of swelling are interdependent.

The influence of carrier oil type on the bioaccessibility of vitamin D3 encapsulated within oil-in-water nanoemulsions prepared using a natural surfactant (quillaja saponin) was studied using a simulated gastrointestinal tract (GIT) model: mouth; stomach; small intestine. The rate of free fatty acid release during lipid digestion decreased in the following order: medium chain triglycerides (MCT) > corn oil ? fish oil > orange oil > mineral oil. Conversely, the measured bioaccessibility of vitamin D3 decreased in the following order: corn oil ? fish oil > orange oil > mineral oil > MCT. These results show that carrier oil type has a considerable impact on lipid digestion and vitamin bioaccessibility, which was attributed to differences in the release of bioactives from lipid droplets, and their solubilization in mixed micelles. Nanoemulsions prepared using long chain triglycerides (corn or fish oil) were most effective at increasing vitamin bioaccessibility. © 2015 Elsevier Ltd. U.S. Department of Agriculture 2014-67021, 2011-67021, 2013-03795, 2011-03539 Alabama Agricultural Experiment Station: 831 This material is based upon work supported by the Cooperative State Research, Extension, Education Service, United State Department of Agriculture, Massachusetts Agricultural Experiment Station (Project No. 831) and by the United States Department of Agriculture, NRI Grants ( 2011-03539 , 2013-03795 , 2011-67021 , and 2014-67021 ). The authors also acknowledge TUBITAK 2214-A Program for providing financial support for Bengu Ozturk.

The production of xanthan gum, an industrially important microbial exopolysaccharide, was enhanced by using Xanthomonas campestris cells adsorbed to cotton fibers. However, the function of xanthan polymers during cell adsorption has not been elucidated. Polyethylenimine (PEI), a cationic polyelectrolyte, was employed to investigate respective effects of fiber surface properties and xanthan polymers during cell adsorption. Adsorption of X. campestris cells to fiber was independent of fiber roughness and hairiness, and the effect of electrostatic interactions between cells and fiber was insignificant. Fiber hydrophilicity was critical in initiating cell-fiber contacts, whereas xanthan polymers enhanced retention of cells on fiber surface. The untreated cotton showed the highest immobilization efficiency and xanthan production.

The diffusion properties of curdlan gels were characterized against its viscoelastic behavior. With increased junction zones involved in rigid crosslinks in higher concentration gels, the three-dimensional structure of curdlan is characteristic. As the gel concentration increases, the intermolecular crosslinking and apparent viscosity increase, reducing mobility of the polymer chains with slower release rates. The scaling laws confirmed that curdlan gel network structure corresponds to that of polymer chains in a good solvent at the semi-dilute regime. Diffusion of the entrapped agent in 6% gels resembled pseudo-controlled release behavior, and a further increase in gel concentration might produce microspheres that support a sustained release.

Natural small molecule surfactants (lecithin and quillaja saponin) were used to fabricate nanoemulsion-based delivery systems from vitamin E acetate using high pressure homogenization. The effect of oil composition (0-100% vitamin E acetate), surfactant type, and surfactant concentration (0.0005-5%) on the mean particle diameter (d32) and vitamin loading capacity was examined. The mean particle diameter had a minimum value at an intermediate vitamin E-to-orange oil ratio in the oil phase: d32 = 0.13 µm for lecithin and 0.12 µm for quillaja saponin at 50% vitamin E. The mean particle diameter decreased with increasing surfactant concentration for both surfactants, with lower levels of quillaja saponin being required to form small droplets. The effect of pH, ionic strength, and temperature on the physical stability of the nanoemulsions was also investigated. Both surfactants formed unstable nanoemulsions at pH 2, which was attributed to loss of electrostatic repulsion due to a reduction in droplet charge. Emulsion instability was also observed at >100 mM NaCl for lecithin and ?400 mM NaCl for quillaja saponin, which was attributed to electrostatic screening. Both systems were stable at temperatures from 30 to 90 °C (pH 7), i.e., no particle growth or creaming was observed. These results provide useful information about the emulsifying and stabilizing capacities of natural surfactants intended for use in the food and other industries. © 2014 Elsevier Ltd. All rights reserved. U.S. Department of Agriculture 2013-03795, 2011-03539 This material is based upon work supported by a United States Department of Agriculture , NRI Grants ( 2011-03539 and 2013-03795 ). The authors also thank the Turkish Government for providing financial support for Bengu Ozturk, and Ingredion and Archer Daniels Midland for supplying the natural surfactants used in this study. We also want to acknowledge TUBITAK 2214-A Program for providing funding for Bengu Ozturk.

Publisher Summary This chapter reviews the bioconversion of whey lactose into microbial exopolysaccharides (EPS). It also emphasizes challenges facing the fermentation process as well as the criteria to be considered to develop it into an effective and valuable bioconversion process. Microbial EPS such as xanthan gum and alginate continue to receive increasing applications in response to the demands for desirable product texture and enhanced processibility of nutritional and healthful food products. These polymers require simple sugars as building blocks and are produced via natural fermentation processes using specific microorganisms. The inherent specificity of the enzymes involved and the controllability of a bioprocess make bioconversion into EPS an ideal candidate for the effective utilization of whey lactose. Bioconversion is considered the most feasible means to effectively transform milk lactose from a low-value feedstock into value-added products. However, the direct fermentation of lactose by participating microorganisms usually suffers from a limited conversion rate as is found in yeast fermentation. The utilization of lactose as the building blocks for the synthesis of microbial EPS thus appears to be a favorable option. Microbial EPS already have many important applications in food, chemical, and pharmaceutical industries, and they continue to find new uses in emerging markets.

The feasibility of using ultrafiltration (UF) to recover protein from poultry processing wastewater (PPW) after primary treatment was investigated. By using polysulfone membrane with 30,000 molecular-weight-cut-off, almost all crude proteins in PPW were retained, subsequently reducing the chemical oxygen demand (COD) in the effluent to less than 200 mg L(-1). Similar to the processing of proteinaceous materials, the average fluxes reached only 100 Lm(-2) h(-1). By identifying the optimal values of key operation parameters, including pH, volumetric flow rate, and transmembrane pressure (6.74, 683 mL min(-1) and 14 psi, respectively) using response surface methodology (RSM), the flux was improved to higher than 200 Lm(-2) h(-1). Although severe membrane fouling was still inevitable after processing, flushing the membrane with a cleaning reagent was found capable of effectively restoring membrane performance.