Package of the Spring 2022

Background and objective: Olive pomace produced in the olive oil extraction process can be used as a natural source for the extraction of bioactive peptides. The objective of this study was to consider the effects of different enzymatic conditions on Olive pomace protein hydrolysis by trypsin.

Material and Methods: In this study for hydrolysis optimization of extracted protein in the olive pomace, it was used Response surface method based on the Box-Behnken design. Degree of Olive pomace protein hydrolysis, amino acid profile was determined. Determination of antioxidant activities in hydrolysate was carried out by1-diphenyl-2-picryl-hydroxyl radical scavenging and Iron (II) chelating activity, as well as, for anti-proliferative activity of supernatant on MCF-7 breast cancer cells were examined.

 Results and Conclusion: The optimal hydrolysis conditions were as follows: time 5h, pH 8.5, and the temperature 39°C; under these conditions, the maximum degree of hydrolysis was achieved 70.62%. 1-diphenyl-2-picryl-hydroxyl radical scavenging activity and Iron (II) chelating activity of olive pomace protein hydrolysis under optimal conditions 42.26± 2.46 and 30.91± 0.26 Obtained at a concentration of 3.5 mg ml^-1, respectively and the highest anti-proliferative activity of olive pomace protein hydrolysis on MCF-7 breast cancer cell was observed at a concentration of 80 mg l^-1. The amino acid analysis indicates an increase in hydrophobic and aromatic amino acid in the hydrolyzed protein. These results demonstrated due to enzymatic cleavage of peptide bonds in olive pomace protein, appreciable antioxidant potential could be achieved.

Background and Objective: Use of pectin has attracted interests in food and nutraceutical industries, owing to its positive effects on stability of dairy drinks and potential health benefits to humans. Furthermore, demands for the production of stable fermented milk drinks during storage period is high. Therefore, the aim of this study was to assess effects of apple and pomegranate pectins as stabilizers on various characteristics of probiotic yogurt drinks.

Material and Methods: Apple and pomegranate pectins at concentrations of 0-0.5% (w v^-1) were added to the probiotic yogurt drinks containing 2% of inulin and 12% of pomegranate juice. Then, rheological behavior, particle size distribution and stability of probiotic yogurt drinks were studied during storage.

Results and Conclusion: Control (treatments with no pectin addition) and probiotic yogurt drinks containing pomegranate pectin (0.1-0.5%) showed Newtonian flow behavior and liquid-like behavior over the frequency range. Probiotic yogurt drinks with apple pectin included shear-thinning flow behavior, gel-like network at low frequencies and mean size particle of 50 mm. The highest G' and G" and stabilities during the storage were achieved in samples containing 0.5% of apple pectin. Results demonstrated that apple pectin included great potentials to be used in industrial production of probiotic yogurt drinks as it improved rheological properties and storage stability of the products. Therefore, use of 0.5% apple pectin is suggested in fermented milk drinks.

Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Lactobacillus farciminis is an obligate homofermentative bacterial species in fermented foods. Although other species such as Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus rhamnosus in Lactobacillus genus have been well characterized, probiotic characteristics of Lactobacillus farciminis still need to investigate. Thus, the objective of this study was to investigate probiotic characteristics and antibacterial activity of Lactobacillus farciminis HN11 isolated from Solanum macrocarpon sauces in Hue city, Vietnam.

Material and Methods: Lactobacillus farciminis HN11 was cultured in Rogosa and Sharpe media and antibacterial activity of the free-cell suspension was assessed against Escherichia coli, Vibrio parahaemolyticus K5, Vibrio parahaemolyticus KS-02, Vibrio owensii KS-05, Vibrio alginolyticus KS-08, Vibrio alginolyticus A1-1 and Staphylococcus aureus using agar well diffusion method. Various probiotic characteristics of the isolate including antibacterial and antioxidant activities, autoaggregation and coaggregation were assessed. Furthermore, hemolytic and amino-acid dercarboxylase activities were assessed for biosafety assessment. The strain abilities to resist sodium chloride and bile salts were assessed as well.

Results and Conclusion: Lactobacillus farciminis HN11 exhibited significant resistance to NaCl and bile salts. The strain expressed high coaggregation abilities for Escherichia coli, significant autoaggregation abilities and antibacterial activities against Vibrio spp. and Escherichia coli. Antioxidant assessment showed that Lactobacillus farciminis HN11 contained high antioxidant activities. This strain was negative for hemolytic and amino-acid dercarboxylase activities. Moreover, ampicillin and chloramphenicol inhibited growth of Lactobacillus farciminis HN11. This study assessed characteristics of Lactobacillus farciminis HN11 and showed its great potentials as a probiotic in fermented foods, enhancing antioxidant and decreasing harmful foodborne bacteria. Although, encapsulation of the strain within acid resistance materials is suggested to better protect it against high-acid contents of the stomach.

Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Fresh garlic includes several preservative and medicinal characteristics; however, its major bioactive components react and convert to other chemical compounds as soon as its tissues are injured. Garlic oil is extracted from garlic and its use in food industries is limited due to its strong odor, taste, volatility and low solubility in aqueous solvents. The aim of the present study was to investigate physicochemical, microbial and sensory properties of low-fat salad dressings containing encapsulated garlic oil in ß-cyclodextrin (GO/ß-CD).

Material and Methods: Five types of salad dressing, including control with no garlic oil, a sample with free garlic oil and three samples containing 546, 818 and 1364 mg GO/ß-CD kg^-1 salad dressing were prepared. Then, pH, color and antioxidant [(peroxide value and thiobarbituric acid reactive substances], antimicrobial (monitoring of four pathogens of Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella enterica) and sensory (taste, color, odor and acceptability by 8-point hedonic test) properties of the samples were assessed during 41 days of storage at 4 ^oC.

Results and Conclusion: The minimum and the maximum color differences belonged to GO/ß-CD-3 sample containing 1364 mg GO/ß-CD kg^-1 salad dressing and sample containing free GO, respectively. Yellowness of samples containing encapsulated GO decreased and direct relationships were seen between decreasing of the sample yellowness and quantity of GO/ß-CD sample. During the storage, pH and peroxide value PV slightly increased. Staphylococcus aureus was the most sensitive strain to free and encapsulated garlic oil. Escherichia coli, Salmonella enterica and Bacillus cereus showed lower sensitivities to the oil. Sensory results showed no significant differences between the tastes of control and free or encapsulated garlic oil and GO/ß-CD-2 samples containing 818
mg kg^-1 encapsulated garlic oil, equal to 90 mg kg^-1 free garlic oil. However, these two treatments included significant differences with samples containing free garlic oil. Results revealed that encapsulation of garlic oil with ß-CD included no adverse effects on taste of the salad dressings. Therefore, GO/ß-CD-2 (818 mg GO/ß-CD kg^-1 salad dressing) can be suggested as a natural antimicrobial agent for the functional mayonnaise production.

Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Aside from ability of lactic acid bacteria to conduct fermentation process, by transforming the raw materials into the final food products, they play an essential role in preservation and also production of distinct food flavors through biotransformation of organic acids and compounds. Functionality of lactic acid bacteria has been associated with their ability to produce a wide array of antimicrobial compounds which acts as a gatekeeper for the integrity of food products and safety for the consumers. Bio-preservation properties of lactic acid bacteria is associated to the production of antimicrobial peptides (including bacteriocins), variety of organic acids, diacetyl, reuterin, low molecular organic metabolites, hydrogen peroxide, and carbon dioxide_, among many others. Different antimicrobials play an essential role not only in the bio-preservation, based on their antibacterial properties, but can be key factors in the anti-mould and consequently reducing the mycotoxins and/or enhance probiotic properties when lactic acid bacteria were applied as. In this review, we aim to present this in a structured manner with different examples for the application of lactic acid bacteria and their antimicrobials metabolites in bio-preservation and medical sector versus bacterial and molds and as part of the probiotics properties.

Results and Conclusion: Lactic acid bacteria are powerful microbial factories, which are able to conduct different fermentation process, to produce variety of beneficial metabolites not just for food biosafety but also for beneficial properties of probiotics and their health promoting properties.

Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Rampant application of antimicrobial drugs in food sectors triggered the development of resistance within the microorganisms in the surrounding environment. Due to the reduced susceptibility towards existing drugs, these microo-rganisms have an increased survival rate when treated. The emergence of this complication in the common food-borne pathogens is worrisome. Several antimicrobial-resistant variants of known infectious bacteria have been discovered. Listeria monocytogenes is one among those 'superbugs' bringing such public health challenges to be tackled. This article aims to review India's current situation and stance regarding the progressive issue of antimicrobial resistance and listeriosis.

Results and Conclusion: The issue of antimicrobial resistance has been recognized at all food industry and health care domain levels. Solutions are constantly being made to combat the obstacle, but the antibiotic resistance crisis does not seem to retard. Despite the awareness, regulations, and restraints implemented across the globe, researches hint towards rising antimicrobial usage and the ensued more threatening infections. India's step towards curbing antimicrobial resistance is at par with other global policies and intends to lower the resistance development rate among all pathogens. Till now, Indian authorities and the public have shown insouciance towards listeriosis. There are no special rules targeting Listeria monocytogenes in India, as opposed to stringent regulations in many western countries. The Indian government and all associated authorities must study and develop plans to establish standards and statutes to control listeriosis. Above all, set up a surveillance system to monitor the causes of food-related illnesses across the country.

Conflict of interest: The authors declare no conflict of interest.

Abstract

Background and Objective: Nowadays, production of ethanol involves many kinds of plant based materials, from conventionally used starchy materials such as rye, wheat, corn and barley to lignocellulose materials serving in second-generation bioethanol production. While raw materials containing simple sugars do not require such complex mashing processes, starchy and lignocellulose materials need significant processing. This review provides an in-depth description of the structures of starchy raw materials commonly used in production of first-generation ethanol. Furthermore, the review describes the structure of lignocellulose biomasses used for second-generation bioethanol production.

Results and Conclusion: Methods commonly used in distilleries to release starch from plant raw materials belong to pressure-thermal pretreatments known as steaming or pressureless liberation of starch methods. Literature shows that amylolysis is strongly determined by the morphology of starch granules. The larger the specific surface area of granules, the greater their susceptibility to amylolysis. The key stage in preparation of starch raw materials for fermentation is starch hydrolysis, which consists of two steps of liquefaction and saccharification. Several species of bacteria (e.g. Bacillus licheniformis) and fungi (e.g. Aspergillus niger) are available that are capable of producing enzymes necessary for starch hydrolysis. Enzymes needed for starch hydrolysis are divided into 1) liquefying enzymes such as α-amylase produced by Aspergillus niger and Bacillus licheniformis or can be found in malt and 2) saccharifying enzymes such as glucoamylase, β-amylase and maltogenic α-amylase of fungal, bacterial and malt origins. Proteases and phytases are used to support mashing process hydrolases of non-starch polysaccharides (xylanase and pullulanase).

Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Disturbance of reactive species produced through various physiological and biochemical processes causes damages to the cells, leading to cell apoptosis. In addition to medical importance, compounds with antioxidant activity can prevent radical species linked damages in food industries. Antioxidants can be described as valuable food preservatives, which promote food nutritional values via preventing oxidation of various diverse contents, majorly lipids, in addition to food deterioration. Due to the high costs and dangerous effects on human health reported for synthetic antioxidants, the search for natural antioxidant compounds has increased. Therefore, the objective of the present review was to overview natural antioxidants from plants and microorganisms as well as their diversity and industrial uses.

Results and Conclusion: Plants and microorganisms are significant natural sources of diverse antioxidants. Nevertheless, the vast diversity of microorganisms and their metabolites as well as their easier manipulations highlight the environmental-friendly antioxidant production techniques from microorganisms that must be revised, compared to plants or synthetic antioxidants. Phenolics and terpenoids are the dominant antioxidants produced in plants, while the microbial antioxidants vary, including carotenoids, polyketides and polysaccharides. This review clearly highlights the competency of microbial bioactive metabolites as the alternative sources of bioactive antioxidants for future of food industries. Elucidating structural and physicochemical characteristics of microbial antioxidants enables the discovery of emerging antioxidants and their mechanisms of action, leading to the disclosure of various strategies in the industries.

Conflict of interest: The authors declare no conflict of interest.