Application of Poly(hydroxyalkanoate) In Food Packaging: Improvements by Nanotechnology

The environmental impact of plastic usage is of critical concern and too great to repair. A shift toward biodegradable food packaging is one option. The aim of this review paper is the study of the potential of biodegradable materials for food packaging. The main characteristics in relation to food usage can be narrowed down to mass transfer (gas and water vapor), thermal and mechanical properties. Among several kinds of biodegradable polymers, poly(hydroxyalkanoate) is one of the favorable candidates for food packaging due to its physical and mechanical properties, biodegradability, with low permeability for O2, H2O and CO2 without residues of catalysts and water solubility. The main focus of this article is to address poly(hydroxyalkanoate) as a potential candidate for food packaging. The need of applying biobased polymers in food packaging is presented in the introduction of this study. We also describe the most common biopolymers providing a brief overview of classification and application. This is followed by an outline of biopolymer production and a main section in which the properties of poly(hydroxybutyrate)-based nanocomposites of greatest relevance to food packaging are discussed. Furthermore, several approaches for improvement of poly(hydroxybutyrate) properties are described and the role of nanotechnology to improve its mechanical properties is presented. Finally, the article concludes with a summary as well as some possible future trends

The Effect of Homogenization Pressure and Stages on the Amounts of Lactic and Acetic Acids of Probiotic Yoghurt

Nowadays the use of probiotic products especially yogurt, due to having wonderful and health properties, has become popular in the world. In this study, the effect of homogenization pressure (100, 150 and 200 bars) and stage (single and two) on the amount of lactic and acetic acids was investigated. Yoghurts were manufactured from low-fat milk treated using high pressure homogenization at 100,150 and 200 bar and at 60°C. The amount of lactic and acetic acids was determined after the days 1, 7, 14 and 21 of storage at 4ºC. The experiments were set up using a completely randomized design. With the increase of pressure and stage of homogenization, the amount of both acids was increased (p<0.01). The greatest amount of lactic and acetic acids during the storage period was observed in the sample homogenized at a pressure of 200 bars and two stages

Alkaline protease production on date waste by an alkalophilic Bacillus sp. 2-5 isolated from soil

This research focused on isolation and characterization of a new strain of Bacillus sp. from alkaline soil, which was able to producing extracellular alkaline protease and amylase from date waste at pHranging from 8 to 11 and temperatures of 20 to 50°C. Purification was conducted by fractionation, concentration, and cation exchange chromatography. The yield and fold of enzyme purification was24% and 50 times, respectively. Molecular weight of purified enzyme was measured by SDS-PAGE as 24.7 kDa. Produced alkaline protease by Bacillus sp. 2 - 5 showed the most caseinolytic activity(without any gelatinolytic activity) at pH > 10. The highest protease activity was achieved in the following conditions: starch concentration (as carbon source) 0.5 g/L, yeast extract and casamino acid(as mixed nitrogen source) 0.5 and 0.3% (w/w), temperature of 45°C at pH 10.7 after 36 h. Based on the optimization studies of production and purification stages, specific and protease activity 143550APU/mg and 57420 APU/mL were achieve

Application of zein antimicrobial edible film incorporating Zataria multiflora boiss essential oil for preservation of Iranian ultrafiltered Feta cheese

Zein based edible film was developed and incorporated with Zataria multiflora boiss essential oil. Mechanical and microbiological characteristics of this biofilms were measured. Increasing concentration of antimicrobial agent in film reduced stretchability, tensile strength and elongation, however increased the thickness and water vapor transmission parameters (P<0.05). Addition of Z. multiflora boiss essential oil, resulted in decreasing the count of viable Salmonella enteritidis, Listeria monocytogenes, Escherichia coli and Staphylococcus aureus in the produced cheese. This investigation concludes that the biofilm containing Z. multiflora boiss essential oil can be highly recommended for packaging of Feta cheese with the improved microbiological and sensory quality. Besides, application of natural plant essential oil has economical and health promoting benefits.Keywords: Zein, Zataria multiflora, cheese, pathogens, mechanical properties

Bench scale production of xanthan from date extract by Xanthomonas campestris in submerged fermentation using central composite design

In this research, xanthan production from date extract was done by using bacterium Xanthomonas campestris PTCC1473 in submerged fermentation (SmF). The impact of different initial concentrations of carbon (date extract) and nitrogen (NH4NO3) sources on cell growth and xanthan production was evaluated. Inoculum (72 h) from the YMB medium was added to the substrate with defined chemical components (nitrogen, sugar, moisture, ash and pH) and incubated. Central composite design (CCD) was used to evaluate the effects of carbon and nitrogen sources on production yield. The results indicate a decrease of cell growth in carbon source concentration up to 50 g/l. The highest cell growth and xanthan production were achieved at 40 g/l concentration of carbon source. The nitrogen source concentration did not cause a significant effect on cell growth; but the highest concentration of xanthan was produced in 0.2 g/l of nitrogen source. The ratio of carbon to nitrogen content had a significant impact on xanthan production. In the optimum condition, maximum concentration of produced xanthan yield and productivity was seen at 11.2 g/l and 8.19 g/kg.day, respectively.Key words: Xanthan, submerged fermentation, date extract, Xanthomonas campestris, central composite design

Evaluation of physicochemical, microbiological and sensory properties of croissants fortified with Arthrospira platensis (Spirulina)

The major physical, chemical, microbiological, and sensory properties of croissants enriched with Spirulina at con - centrations ranging between 0.5 and 1.5% were evaluated. The results showed that the use of A. platensis biomass for the production of croissants improved the textural and organoleptic properties of the final products. Spirulina for - tification also increased the protein and moisture levels and water-holding capacity, whereas it decreased the crumb firmness and lightness of croissants. Optimum sensory results were obtained when Spirulina was applied at a rate of 1%. Besides these benefits, the A. platensis biomass enhanced the levels of biologically active substances (i.e. essential amino acids, chlorophyll, phycocyanin, carotenoids, minerals, vitamins, and essential fatty acids) in croissant samples. To our knowledge, this is the first scientific study on Spirulina-fortified croissants

Enzyme production from food wastes using a biorefinery concept

According to Food and Agricultural Organization (FAO), one-third of food produced globally for human consumption (nearly 1.3 billion tonnes) is lost along the food supply chain. In many countries food waste is currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy. However, these two options are facing more and more economic and environmental stresses. Due to its organic- and nutrient-rich nature, theoretically food waste can be converted to valuable products (e.g. bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals and fuels) through various fermentation processes. Such conversion of food waste is potentially more profitable than its conversion to animal feed or transportation fuel. Food waste valorisation has therefore gained interest, with value added bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals, and fuels. Therefore, the aim of this review is to provide information on the food waste situation with emphasis on Asia–Pacific countries and the state of the art food waste processing technologies to produce enzymes

Safety assays and nutritional values of mycoprotein produced by Fusarium venenatum IR372C from date waste as substrate

BACKGROUND: Nutritional and environmental benefits of mycoprotein verify its beneficial role on the health of humankind in the next decades. Agro-industrial wastes can be used as cheap substrates to decrease the total cost of product. However, fungi may produce toxins or lead to allergic reactions in consumers. Therefore, the study of the safety and nutritional aspects of this product are very important. RESULTS: Fusarium venenatum IR372C was cultured on date wastes and ammonium salts in submerge fermentation. The safety and nutritional issues of produced mycoprotein were investigated including allergy tests and analyses of toxins, as well as existence of toxin genes, and content of heavy metals, metals, amino acids and fatty acids. The results showed that fumonisin genes in F. venenatum IR372C remain without any gene expression during 1 week fermentation. Zearalenone and deoxynivalenol cannot be detected in the fermentation medium after 3 weeks. Prick tests on 30 volunteers demonstrated no sensitivities to mycoprotein. The content of lead was 658 μg kg�1 as the highest heavy metal followed by arsenic, cadmium and mercury at 161, 30.57 and 0 μg kg�1, respectively. Produced mycoprotein includes essential amino acids at appropriate contents and the ratio of unsaturated to saturated fatty acid was nearly 2:1. Also, calcium, iron, magnesium and zinc were found in mycoprotein, which could have health beneficial impacts on consumers. CONCLUSION: This study has provided information on safety aspects of mycoprotein production by F. venentaum IR372C from date wastes. However, further studies with focus on long-term clinical benefits of diets containing mycoprotein are necessary. © 2020 Society of Chemical Industry. © 2020 Society of Chemical Industr