Electrospinning of glutelin-hordein incorporated with oliveria decumbens essential oil: characterization of nanofibers

peer-reviewedIn this study, electrospinning of hordein and glutelin extracted from barley was carried out. Different ratios of the glutelin-hordein blends (25:75, 30:70, 35:65) were tested and the operation parameters including voltage, ejection flow rate and needle-to-collector distance were optimized. According to the scanning electron micro-scope images, the glutelin-hordein 25:75 blend generated at the voltage of 15 kV, the needle-to-collector distance of 150 mm and the ejection rate of 1 mL/h was selected for the fabrication of uniform nanofibers. The apparent viscosity at the ejection point was decreased with increasing the glutelin concentration from 25 to 35 %. Moreover, the Oliveria decumbens essential oil (ODEO) with different loading concentrations (2–4 % (v/v)) was incorporated into the protein blend. Fourier-transform infrared spectra demonstrated the occurrence of the interactions of proteins the ODEO. The encapsulation efficiency of ODEO in the nanofibers was 79.30 %. The presence of ODEO led to inhibition the growth of Staphylococcus aureus, Escherichia coli and Bacillus cereus in a synthetic medium. The optimal nanofibers showed high antioxidnat activity. The results herein showed the possibility of the production of electrospun nanofibers using barley proteins with promising (bio)functionalities for the active food packaging applications

Yeast-Lactobacillus Co-Cultures as in situ Ethanol Producers for Flavor Ester Synthesis using Lipase in Fermented Milks

Background and objective: Nowadays, novel biotechnological methods are preferred for flavoring productions since traditional methods include disadvantages. The aim of this study was to assess in situ biosynthesis of natural fruity flavors in fermented milks using microbial co-cultures and lipase enzyme. Materials and methods: Trans esterification of milk fats with ethanol was carried out to develop fruity flavors in ultra-high-temperature whole milks using lipase of Palatase coupled with ethanol fermentation. Kluyveromyces marxianus NCYC 1425 was used to produce in situ ethanol in co-cultures with Lactobacillus fermentum PCC or Lactobacillus paracasei L26. Effects of co-culturing on cell viability and fermentation progress were assessed using enumeration of viable cells and measurement of pH in samples at 0, 24 (Palatase addition) and 48 h (end of fermentation). Headspace solid phase microextraction-gas chromatography (SPME)-MS/FID was used for ester, ethanol and free fatty acid analyses at the beginning and end of the fermentation. Standard curve of ethanol was used to assess the products in terms of being Halal. Results and conclusion: Kluyveromyces marxianus included synergistic effects on Lactobacillus paracasei growth as well as antagonistic effects on Lactobacillus fermentum growth. Antimicrobial effects were seen in Kluyveromyces marxianus-Lactobacillus paracasei co-cultures when Palatase was added. Palatase significantly increased ester levels of the fermented samples. The co-cultures did not include significant differences in shorter chain ester levels (esters of 4-7 carbon chain fatty acids); in contrast, Kluyveromyces marxianus- Lactobacillus fermentum resulted in higher levels of longer chain esters. Although the Kluyveromyces marxianus cultures resulted in higher ester levels compared to that its co-cultures did, the cultures can be used as appropriate adjunct cultures with Lactobacillus cultures to boost flavor ester synthesis. This flavor synthesis can be an appropriate alternative for artificial flavoring agents

Wild pistachio (Pistacia atlantica mutica) oil improve metabolic syndrome features in rats with high fructose ingestion

Objective(s): Metabolic syndrome is a multiplex risk factor for diabetes and cardiovascular disease. Since some dietary fats such as mono-unsaturated fatty acids (MUFA) modify metabolic syndrome components the aim of the present study was to evaluate  the preventive effects of mixture, kernel and hull oils of wild pistachio (WP) (Pistacia atlantica mutica) as good sources of MUFA on different features of this abnormality in rats under induction. Materials and Methods: In this study rats were randomly assigned to six groups with 12 animals per group. Metabolic syndrome was induced by fructose solution in groups 2, 3, 4, 5, and 6. Group 3 received sunflower oil and groups 4, 5, and 6 received mixture, hull and kernel oils of WP (2 ml/kg/day), respectively, for 10 weeks. Then, lipid profiles, glycemic indices, oxidative stress and inflammatory parameters were measured using standard laboratory tests.Results: Different forms of WP oil induced hypotriglyceridemia, but the hypocholesterolemia effect was seen only in the mixed and kernel oil groups. Kernel oil also significantly reduced LDL and HDL cholesterol (

Evaluation of Physicochemical and Microbiological Properties of Milk Collected from Traditional Sale Centers in Shiraz, Southern Iran

Background: Milk and dairy products have important roles in the human diet. Therefore, quality control and monitoring of the hygiene standards of dairy products during production, transportation, storage, and distribution are of particular importance. Due to the poor sanitary conditions during storage, improper heat treatment, and post-contamination, traditional dairy products can be a good media for the growth of a wide range of microorganismsMethods: This study aimed to evaluate traditional dairy products in Shiraz including 25 samples of raw cow's milk (cold and warm seasons), for significant risk factors. Physical, chemical, and microbial tests were performed according to the national standard of Iran.Results: The trend of changes in fat, solids-non-fat, and freezing point of raw milk samples in cold seasons was more than in hot seasons. In addition, instability against alcohol and somatic cells was higher in warm-season samples. The milk density was unrelated to seasons. The microbial quality of the samples was not within the national standard of Iran, which could be due to improper storage conditions and lack of cold chain control from livestock to supply centers. PCR analysis confirmed the absence of two pathogenic bacteria Escherichia coli O157:H7 and Listeria monocytogenes in raw milk samples.Conclusion: According to the present results, the quality of traditional dairy products distributed in Shiraz is not good. Therefore, having a specialized technical manager for traditional dairy units is essential. Furthermore, more serious and more supervision is needed from livestock to distribution centers by relevant organizations and centers