applied food biotechnology
Volume:9 Issue: 4, Autumn 2022

Fermentation,smoking and salting processes of rawmaterialsarepartsof the preservation processes that are essentialfor the production of final products in south European countries. Originally, fermentation of meat products was used for long-term preservation and safe storage. However, gastronomical characteristicsof the fermented meat products are now essential in achieving favorableflavor, aroma, color and structure of the salamisthatare preferred by the consumers. The emphasis is onthegastronomic characteristics that are resulted from various combinationsof raw meats, specific spices and the natural microbiota or fermentation processes carried out using specific starter cultures. The objectives of this review were to provide information regarding origin of lukanka, a Bulgarian semi-dried fermented meet product, knowledge about microbiological specificity of the product and examples of beneficial characteristics associated with lactic acid bacterial isolated fromlukanka.

Meat starter cultures typically consist of seven bacterial species belonged to Lactobacillus, Leuconostoc, Staphylococcus,Enterococcus, Lactococcus, Micrococcusand StreptococcusSpp. Various lactic acid bacteria were isolated from lukankaand assessed regarding their safety and beneficial characteristics. During the maturation of fermented meat products, complex fermentation processes ensue from the interactions between the bacterial starter cultures, residual enzymes in the muscles and fat tissues andavailable bacterial enzymes. Roles of beneficial characteristics of lactic acid bacterial from lukankawere discussed as essential for the designation of lukankaas a functional food product. Traditional fermented meat products are specific ecological systems, where interactions between various bacterial strains and food matrices result in formation of the unique characteristics of the final product. Analyzing traditional fermented meat sausages from the perspective of 21 century science point of view, these foods can be addressed as examples of functional food products, providing nutritional, gastronomical and beneficial advantages to the consumers

In recent years, green synthesis of nanobiomaterials has received more attentions than chemical synthesis due to their ecofriendly and compatibility. The aims of this study were to investigate synthesis of nanobiomaterials from probiotics and characterize these nanobiomaterials.

Bacillus subtilisand Bacillus coagulanswere cultured in media containing insoluble calcium phosphate and urea, and produced nano-hydroxyapatite and nano-calcite. Productions were surveyed in three stages. First, produced particles were assessed on the surface of the dried bacteria at room temperature. In the second stage, dried bacteria were burned at 600ºC. In the final stage, hydroxyapatite was purified using nanofilters. Characterization and elemental analysis of the biomaterials were studied using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectroscopy, energy dispersive X-ray and X-ray fluorescence.

It was shown that nano-calcite and braided nano-hydroxyapatite on the dried biomass surface and nano-hydroxyapatite were made only in media containing insoluble calcium phosphate supplemented by urea, which was induced by phosphatase and urease. Removing organic matters by heat treatment led to the further purity of the particles. The X-ray fluorescence results revealed purity of the nano-hydroxyapatite, which was achieved by filtration of particles after burning. The ratio of calcium to phosphorus in B. coagulance sample reached 1.8, which was close to stoichiometric hydroxyapatite.Sincenanobiomaterials are made from probiotics, these particles can be appropriate candidates to use in food industries, sanitation and medicine. Braided nano-hydroxyapatite can substitute needle-like types of food additives for infants and elderly people because of its safety

Gamma aminobutyricacid is a non-protein amino acid with various physiological characteristics that is used as a synthetic supplement for healing anxiety, acute stress and sleeping disorders. Due to the demand for natural bioactive components, producing gamma aminobutyric acid enriched foods and supplements via biological methods has been popular in recent years.

In this study, one factor at a time approach was used to study effects of various protein hydrolysates, including soy protein isolate,whey protein concentrate and caseinat different concentrations (1-5% wv-1), fermentation time (24, 48 and 72 h)and inoculum size (1, 3 and 5% v v-1) on gamma aminobutyric acid synthesis. Then, the most effective parameters such as concentrationof soy protein hydrolysate, inoculum size and fermentation time at various levels were studied using central composite design based response surface methodology for gamma aminobutyric acid synthesis by Lactiplantibacillus plantarumMCM4.

Of various protein hydrolysates, soy protein hydrolysate was more appropriate for gamma aminobutyric acid synthesis. Moreover, higher gamma aminobutyric acid contents were achieved when soy protein with extended enzymatic hydrolysis for 6 h (soy protein hydrolysate6)was used as the substrate. The polynomial mathematic model could predict gamma aminobutyric acid synthesis successfully. Optimization using central composite design indicated that the maximum gamma aminobutyric acid synthesis yield (19.4 mg 100 ml-1) was achieved under the optimum conditions (fermentation time of 29 h, inoculum size of 3.65% v v-1and Soy Protein Hydrolysate 6 concentration of 3.9% w v-1). Overall,Lactobacillus plantarumMCM4 was suggested as a novel lactic acid bacteria species to produce gamma aminobutyric acid from inexpensive sources.

Lactic acid bacteria have recently become one of the major topics of discussion in fields of health, food industry, science, animal husbandry and agriculture. Lactic acid bacteria have been widely used in fermentation of various types of food products fromanimals, fish and plants that act as preservatives and include positive effects on human health and beauty. One source of lactic acid bacteria is Mystacoleucus padangensisfish from Singkarak Lake, West Sumatera, Indonesia, where a probiotic bacterium of Limosilactobacillus fermentum with antimicrobial potential is isolated. The aim of this study was to assess antimicrobial potential of Limosilactobacillus fermentum isolated from Bilih fish from Singkarak Lake, Indonesia.

Methods of this study were as follows: isolation of lactic acid bacteria from Bilihfish from Singkarak Lake, followed by antimicrobial activity assessment of the raw bacteriocin supernatant. Then, 16S rRNA was used to assess species of the lactic acid bacteria isolates. From the three samples, one sample of Isolate IB1, with potential antimicrobial activity was reported.

Results of the study showed that the morphological and biochemical characteristics of lactic acid bacteria included Gram-positive, bacilli form and catalase-negative belonged to the group of homofermentative bacteria. The greatest antimicrobial activities were shown by IB1 Escherichia coli0157:H7 (27.29 mm), Staphylococcus aureus ATCC 25923 (14.17 mm) and Listeria momocytogenesCFSAN 004330 (11.44 mm) while the diameter of inhibition zone by the supernatant of Lactic acid bacteria Escherichia coli0157:H7 crude bacteriocin was 16.89 mm while Staphylococcus aureusATCC 25923 did not form inhibition zone. The observed antimicrobial activity was 17.19 mm for Listeria monocytogenesCFSAN 004330at neutral pH. Results of the molecular identification using 16S rRNA showed that the isolated lactic acid bacteria included similarities with Limucilactbacillus fermentumstrain 1705916S, which included antimicrobial potentials against pathogenic bacteria.Limosilactobacillus fermentum 1705916S can be used as an antidiarrheal and antityphoid agent in humans and as a natural preservative in foods.

Disposal of fishery wastes is one of the environmental challenges.Converting wastes into valuable products is an economical solution to solve this environmental problem. One of the wastes of fishery products is shrimp shell waste, which contains large quantities of chitin. Chitin and its derivative, chitosan, include several uses in various industries, especially the food industry. The aim of the present study was to extractchitin from shrimp shell wastes usingco-fermentation with mixed microbial cultures. Chitosan production by deacetylation of chitin using various concentrations of NaOH was another aim of this study.

Batch fermentation was carried out to extract chitin from the shrimp shell using mixed cultures of two microorganisms, Lactiplantibacillus plantarumPTCC 1745 andBacillus subtilisPTCC 1720. The Logistic model was used to assess the microbial growth rate.To prepare chitosan from chitin, deacetylation was carried out using NaOH solution. Morphological structures of the chitin and chitosan were studied using scanning electron microscopy. Functional groups of the synthesized chitin and chitosan were assessedusing Fourier transform infrared spectroscopy.

High levels of demineralization and deproteinization were achieved using co-fermentation with the mixed microbial populations at 60 g.l-1of glucose concentration. Chitin was produced with high purity and the protein and ash contents included 1.43 and 1.26%, respectively. Data predicted by the Logistic model were fairly matched the experimental data. A maximum cell growth rate of 0.065 (h-1) was achieved at 60 g.l-1of initial glucose concentration at 35 °C. The optimal value of deacetylation (88.2%) was achieved using 50% NaOH solution at 100 °C. The results showed that the use of mixed culture of acid-producing and proteolytic microorganisms is highly effective for extracting chitin from shrimp shell waste.

Helicobacter pyloriinfection is of widespread diseases in the world. The most common treatment for remediation of its symptoms is administration of antibiotics, which are not efficient enough in some patients and resulted in antibiotic resistance. Given the adverse effects arising from antibiotics in clinical studies, we aimed to fabricate chitosan-and pectin-based micro-particles containing Zataria multifloraextract for suppression of Helicobacter pyloriin the laboratory.

Chitosan and pectin micro-capsules alone and in combination with Zataria multifloraextract were prepared by spray dryer. The powders were further characterized by FT-IR, zeta sizer, and scanning electron microscope. Simulated gastric fluid was also prepared for evaluation of anti-Helicobacter potency of the samples.

Chitosan 1% w v-1+ 0.5 mlZataria multifloraextract (CE0.5), pectin 1% w v-1+ 0.3 ml Zataria multifloraextract (PE0.3), and pectin 1% w v-1(P1) could significantly suppress the bacteria under simulated gastric condition. The least survivability of Helicobacter pyloriwas 45.4% and achieved for CE0.5, followed by 45.70% and 46.6% for PE0.3 andP1, respectively. Electrostatic charge of the biopolymers and phenol compounds of the extract greatly affected the integrity of bacterial cell wall. According to FT-IR spectra, Zataria multifloraextract was physically entrapped in chitosan and pectin layers, which helped its better antimicrobial activity invitro. Regarding the significant anti-Helicobacter activity of our selected formula, they would be considered as complementary treatment for antibiotics in eradication of Helicobacter pyloriinfection. Although further in vivoexperiments are required to validate the current findings.