فهرست مطالب

applied food biotechnology - Volume:2 Issue: 4, Autumn 2015

applied food biotechnology
Volume:2 Issue: 4, Autumn 2015

  • تاریخ انتشار: 1394/09/07
  • تعداد عناوین: 7
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  • Martin Koller, Lukas Marsalek Pages 3-10
    The article addresses the contemporary quest for inexpensive carbon feedstocks to be used for cost-efficient bio-mediated polymer production. In particular, the work shines a light on crude glycerol, a surplus stream of the globally tremendously emerging biodiesel industry. Crude glycerol can be upgraded to a convenient substrate for microbial polyhydroxyalkanoate (PHA) production without interfering with food- or feed production. The article covers the challenges of crude glycerol as feedstock in biotechnology, and gives an insight into the metabolic background of glycerol-based PHA-production. Particularities of glycerol-based PHA biosynthesis, such as the characteristic formation of low-molar mass polyesters, are also discussed in the presented work.
    Keywords: Biodiesel, Biopolyester, Glycerol, Molar mass, Polyhydroxyalkanoates (PHA)
  • Rouha Kasra, Kermanshahi, Elahe Mobarak, Qamsari Pages 11-19
    Disease caused by consuming microbial contaminated food has increased significantly in recent years due to changes in the livelihoods and eating habits of the human populations. Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica are three of the most important foodborne bacterial pathogens and can lead to foodborne diseases. Increased use of antibiotics, has led to development of bacterial resistance to antibiotics. Therefore, there is growing interest in the development of new types of effective and nontoxic antimicrobial compounds.Nowadays, the most extensive research and commercial practices are based on probiotic bacteria. Probiotics, specifically lactic acid bacteria are widely used in the food industry for fermentation but have gained attention from health professionals because of their potential beneficial effects. Now probiotic therapy is thought to be an effective way to improve the gut health and an alternative to antibiotic treatments. They contribute to food safety by their ability to inhibit the growth of several other bacteria. LAB can be used as protective cultures to compete with potential pathogens and other undesired organisms, thereby increasing the safety of the food product.
    Keywords: Bactericine, Biofilm, Food born pathogen, Lactic acid bacteria, L.monocytogenes
  • Shafieh Mansoori, Fatemeh Yazdian, Majid Azizi, Mojgan Sheikhpour, Gassem Amoabediny, Javad Hamedi, Behnam Rasekh Pages 21-26
    Monascus purpureus is a fungus that had been cultured on the rice in eastern Asian countries from thousand years ago and used as a food for long years. The fungus produces very valuable metabolites with polyketide structure. The most of important metabolite is Monacolin K, Lovastatin or competitive inhibitor of HMG-CoA reductase (an affective enzyme in cholesterol synthesis). This metabolite have properties including reducing blood cholesterol, treatment of progressive renal disease, the potential for treat a variety of tumors, preventing infection, vascular diseases and bone fractures. In this study, Monascus purpureus PTCC5303 has been used for lovastatin production in liquid fermentation. The nutritional concentration that were significant in biomass and lovastatin production included maltose and MgSO4, were optimized by Response Surface Methodology (RSM) in a milibioreactor. The optimum concentration of maltose and MgSO4 wereobtained 10 g/L and 0.78 g/L, respectively. According to our results, maximum lovastatin production under optimum condition containing maltose 10 g/L, peptone 5 g/L, MgSO4.7H2O 0.78 g/L, MnSO4.H2O 0.5 g/L, KH2PO4 4 g/L, thiamine 0.1 g/L, and pH=7 at 30°C, 130 rpm and flow rate 1.8 L/min was obtained to be 309 µg l−1 after 10 days of fermentation period.
    Keywords: Monascus purpureus, Optimization, Bioreactor, OTR, Lovastatin
  • Maryam Yari, Jamshid Fooladi, Mohammad Ali Kargar Motlagh Pages 27-32
    Because of poor survival of probiotic bacteria, microencapsulation evolved from the immobilized cell culture technology used in the biotechnological industry. Two probiotic strains, Bifidobacterium (BB-12) and Lactobacillus acidophilus (LA-5) were immobilized in calcium alginate by extrusion method. Encapsulation parameters and efficacy of this method were evaluated. Growth factors of these two bacteria were also measured by culturing in 10-L fermenter. Growth curves were obtained with respect to optical density and dry biomass weight. Encapsulation yield was over than 60% in each experiment. Scanning electron microscopy (SEM) of Entrapment of cells in alginate matrix and cross-sections of dried bead were obtained and illustrated. Bifidobacterium have been shown better biotechnological properties.
    Keywords: Alginate, Fermenter, Microencapsulation, Probiotic
  • Somayeh Tajik, Fatemeh Zarinkamar, Vahid Niknam Pages 33-37
    Saffron (Crocus sativus L.), the most valuable medicinal food product, belongs to the Iridaceae family which has been widely used as a coloring and flavoring agent. The stigmas contain three major compounds, crocins (carotenoid compound responsible for color), picrocrocin (responsible for taste) and safranal (responsible for odor). It has been used for medicinal purposes, as a spice and condiment for food and as a dye since ancient times. Numerous studies have shown crocins as main carotenoids of saffron to be capable of a variety of pharmacological effects, such as protection against cardiovascular diseases, inhibition of cancer cell development. Salicylic acid (SA) is a signaling molecule and a hormone-like substance that plays an important role in the plant physiological processes. In order of importance of saffron as valuable product, the aim of this study is to investigate effects of salicylic acid application (0.01, 0.1 and 1 mM) on crocin and safranal content and antioxidant activity of stigma. Results showed that SA application at 1 mM were the most effective treatments in increase of crocin content and stronger antioxidant activity, but SA had a negative effect on safranal content and the highest quantity of this compound was observed in control plants.
    Keywords: Antioxidant activity, Crocin, Crocus sativus, Picrocrocin, Safranal, Salicylic acid
  • Saeed Abbasalizadeh, Mohammad Amin Hejazi, Mahdi Pesaran Hajiabbas Pages 39-47
    The potential of bulk starter fermentation strategy for production of a cost-effective and GRAS source of β-galactosidase from a starter culture strain Lactobacillus bulgaricus was investigated. Three different media were selected and the strain, L. bulgaricus DSM 20081 was cultivated in these media under pH-controlled condition (pH = 5.6) at 43°C. The media were: bulk starter medium based on skim milk + whey, bulk starter medium based on whey, and skim milk. Growth and β-lactic acid production parameters were estimated from experimental data with the Garcia and Luedeking-Piret models, respectively. β-galactosidase production kinetics was also simulated using models based on biomass concentration and lactic acid production. Growth in the bulk starter medium based on skim milk + whey resulted in a higher rate of lactic acid production (7.35 ± 0.23 mg lactic acid ml-1 media h-1) and β-galactosidase activity (800.1± 0.7 nmol ONP ml-1 media) compared to the other two media (P<0.01). Simulation of β- galactosidase production based on rate of lactic acid production resulted in very good agreement with experimental data for all three tested media. The results revealed the potential of bulk starter fermentation strategy and skim milk + whey based medium for in-house and relatively low cost production of food-grade β-galactosidase by dairy plants.
    Keywords: Biochemical, Bioprocess Engineering
  • Ali Izadi, Sobhan Mosayebi Dorcheh, Hamid Rashedi Pages 49-55
    In this study, substrates concentration profile has been studied in a porous matrix containing immobilized amyloglucosidase for glucose production. This analysis has been performed by using of an analytical method called Least Square Method and results have been compared with numerical solution. Effects of effective diffusivity (), Michael's constant (), maximum reaction rate () and initial substrate concentration () are studied on Soluble Starch and Dextrin concentration in the spherical support. Outcomes reveal that Least Square Method has an excellent agreement with numerical solution and in the center of support, substrate concentration is minimum and increasing of effective diffusivity and Michael's constant reduce the Soluble Starch and Dextrin profile gradient.
    Keywords: Amyloglucosidase, Immobilized enzyme, Least square method, Substrate concentration