Review Article

Xylooligosaccharidesand Arabinoxylanoligosaccharides and Their Application as Prebiotics

Bradley Arthur Saville, Sandra Saville

Applied Food Biotechnology, Vol. 5 No. 3 (2018), 5 July 2018, Page 121-130

Background and Objective: Xylooligosaccharides and arabinoxylanoligosaccharides have been subject to nearly 30 years of in vitro and clinical trials, and advances in process technology have led to more widespread commercial availability. This review was conducted to examine xylooligosaccharides and arabinoxylanoligosaccharides as next generation prebiotics.

Results and Conclusion: Xylooligosaccharides and arabinoxylanoligosaccharides are based upon 5-carbon sugars, and their microbial utilization in the digestive tract is thus fundamentally different from prebiotics such as fructooligosaccharides, inulin, and resistant starch that are oligomers/polymers of 6-carbon sugars connected by α bonds. Five carbon sugars and oligosaccharides connected by β bonds are more narrowly utilized; xylooligosaccharides and arabinoxylanoligosaccharidesare especially effective for selective feeding of Bifidobacteria, although they can also be used by some strains of Lactobacilli and other bacteria. Clinical studies on xylooligosaccharides and arabinoxylanoligosaccharides report beneficial impacts upon digestive health, management of blood sugars and lipids, beneficial modification of immune markers, and benefits for laxation. These outcomes have typically been observed at 1-4 grams per day, a lower dose than required for other prebiotics such as fructooligosaccharides and inulin. The lower dose requirement for clinical efficacy also provides advantages in terms of product formulation and more options for delivery of a clinically beneficial dose to consumers.

Original Article

Antibacterial Effect of Teucrium polium Essential Oil and Lactobacillus casei Probiotic on Escherichia coli O157:H7 in Kishk

Nava Sadrizadeh, Sima Khezri, Parvin Dehghan, Razzagh Mahmoudi

Applied Food Biotechnology, Vol. 5 No. 3 (2018), 5 July 2018, Page 131-140

Background and Objective: In recent years, there has been a rapid development in prevention of bacterial growth and spoilage in foods by the application of preservatives. Essential oils, which are known to be harmless for human, have shown positive health effects in addition to their preservative role. Likewise, probiotics exert improvement in both food product and health level of consumers. With reference to these it is important to do more research on various effects of endemic essential oils on traditional food products. A survey was carried on effect of essential oil and combination of essential oil and probiotics on growth of Escherchia coli O157:H7.

Material and Methods: Kishk samples treated with Teucrium polium essential oil (75 and 150 mg l-1) and Lactobacillus casei (108 -109 CFU ml-1) were stored up to 20 days at 4°C and the effect of Teucrium polium essential oils and probiotic fermentation on Escherchia coli O157:H7 counts were investigated.

Results and Conclusion: Teucrium polium essential oils and probiotic fermentation reduced the number of Escherichia coli during the cold storage time. The combination of Teucrium polium essential oil and probiotics showed stronger effect rather than individually added. Initial count of inoculated Escherchia coli was 6.39 log CFU g-1. Essential oil compounds of Teucrium polium included Spathulenol, Epizonaren and Bicyclo hept-3-en-2-ol in 18.39, 9.62 and 6.76%, respectively. After 20 days storage at 4°C, the number of Escherchia coli in probiotic, combination of probiotic and essential oil (150 mg l-1) and control samples decreased from 6.39 log CFU g-1 to 4.95, 4.30 and 5.8 log CFU g-1, respectively. An increase in acidity and decrease in pH were observed for all samples (p≤0.05). Based on organoleptic tests, the most accepted sample was included 75 ppm of essential oil and probiotic. According to the antibacterial effect of essential oils extracted from plant and probiotic fermentation, it was predictable that they could decline the Escherchia coli count especially in fermented dairy products. Also, due to its probiotic nature, Kishk would bring numerous health advantageous for consumer.

Chitin Extraction from Lobster Shell Waste using Microbial Culture-based Methods

Jayashree Chakravarty, Chen-Lu Yang, Jacob Palmer, Christopher John Brigham

Applied Food Biotechnology, Vol. 5 No. 3 (2018), 5 July 2018, Page 141-154

Background and Objective: Lobster shell waste from seafood processing industry was used as the source of raw material to produce the valuable biopolymer chitin. Chemical and biological treatments of lobster shell waste were performed and compared.

Material and Methods: The chemical method required the use of aqueous solutions of HCl and NaOH. Biological treatment included the use of co-cultures with a protease-producing bacterium, either Bacillus megaterium NH21 or Serratia marcescens db11, and an organic acid-producing bacterium Lactobacillus plantarum. The optimal culture conditions, including co-cultivation strategies and glucose concentrations, were identified to improve efficiency of lobster shell deproteinization and demineralization.

Results and Conclusion: Overall, the successive treatment with a combination of Serratia marcescens db11 and Lactobacillus plantarum resulted in the best co-removal of CaCO3 and proteins and chitin yield (82.56%) from lobster shell biomass, with total deproteinization of 87.19% and total demineralization of 89.59%. The results from the proof-of-concept study described here suggest that microbial treatment may be an environmentally friendly alternative to the chemical method of chitin extraction.

Effects of Probiotic Cells on the Mechanical and Antibacterial Properties of Sodium-Caseinate Films

Esmail Abdollahzadeh, Seyed Mahdi Ojagh, Abbas Ali Imani Fooladi, Bahareh Shabanpour, Maryam Gharahei

Applied Food Biotechnology, Vol. 5 No. 3 (2018), 5 July 2018, Page 155-162

Background and Objective: Food processing conditions such as heat, mechanical or osmotic stress can lead to considerable losses of probiotics’ survival in food. Recently, the addition of probiotics into edible films has been proposed as an emerging technology for the delivery of probiotic cells. In this study, Lactobacillus acidophilus and Lactobacillus casei cells were incorporated into sodium caseinate matrix to develop a probiotic-based film which can improve food safety.

Material and Methods: Probiotic cells were separately added to the film forming solutions and the active films were prepared by casting method. The physical, optical and mechanical characteristics of the films were examined. Color properties were determined using a colorimeter and the mechanical properties of the films were evaluated by an Instron Universal Testing Machine. The viability of Lactobacillus acidophilus and Lactobacillus casei in the films was determined during a period of 12 days. The antibacterial activities of the films were also tested against Listeria monocytogenes on Trypticase Soy Agar medium at 4°C.

Results and Conclusion: Results demonstrated that lactic acid bacteria cells remained viable during a storage period of 12 days (> 4 Log CFU cm-2). The incorporation of lactic acid bacteria cells into the film polymer had no significant effect on tensile strength (p>0.05) whereas it significantly improves the appearance of films. Indeed, samples covered with the lactic acid bacteria film displayed higher anti-listerial activity than the control group on day 6 of preservation (p≤0.05). These findings show that the sodium caseinate film containing lactic acid bacteria cells can be used as a new effective packaging method for improving food safety.

Effect of Chitin and Chitooligosaccharide on In vitro Growth of Lactobacillus rhamnosus GG and Escherichia coli TG

Otto Selenius, Jaakko Korpela, Seppo Salminen, Carlos Gomez Gallego

Applied Food Biotechnology, Vol. 5 No. 3 (2018), 5 July 2018, Page 163-172

Background and Objective: Given the rising tendency of using insects as food, research regarding the food safety issues and health implications of edible insects are necessary. Insects have an external skeleton that is mainly composed of chitin- a nontoxic, fiber-like polysaccharide. Chitin and its derivative compounds can take part in maintaining healthy gut microbiota, by promoting or inhibiting the growth of several gut bacteria depending on the chitinous substrate. Healthy composition of gut microbiota can prevent intestinal disease states and food digestion problems. The aim of the study is to characterize the impact of chitin and chitooligosaccharides on the growth of two gut bacteria Lactobacillus rhamnosus GG and Escherichia coli TG, to provide further understanding on possible outcomes of consuming insects.

Materials and Methods: Micro plate wells were prepared with tryptone soy broth in 0.5 and 0.1% wv-1 chitin concentrations and in 0.5, 0.1, and 0.05% wv-1 chitooligosaccharide concentrations. Bacteria were added and the growth parameters of Lactobacillus rhamnosus GG and Escherichia coli TG were obtained by measurement of optical density at 600 nm in 37°C.

Results and Conclusion: Chitooligosaccharides enhanced the growth of Lactobacillus rhamnosus GG and inhibited the growth of Escherichia coli TG in the lowest tested concentration of 0.05% wv-1. Chitin completely inhibited the growth of both bacteria in the lowest tested concentration of 0.1% wv-1. Chitooligosaccharides appear promising as potential prebiotic compounds associated with insect food products. Chitin has a strong antibacterial effect on tested bacteria. However, the In vitro results should be verified in well-designed human studies.

Background and Objective: For the first time, a detailed study of the antimicrobial metabolites produced by probiotics was carried out as an alternative natural way of chemical additives and to support consumer health. The study was undertaken using Lactobacillus acidophilus, Bifidobacterium animalis ssp. Lactis BB12, as well as and antimicrobial products as protective cultures to reduce the risk of food poisoning in minced meat.

Materials and Methods: Samples of minced meat were stored at 4°C. The microbiological analysis of probiotics and pathogens bacteria was performed in days 0, 3, 7 and 14. In these periods, pH parameter and antimicrobial activity of the probiotics were analyzed.

Results and Conclusion: During the cold storage, the counts of inoculated pathogens in the minced meat samples in co-culture with each specific probiotic decreased at different levels; some had significant decrease (p≤0.05) and some others showed no significant change (p>0.05). The probiotics displayed the ability to produce antibacterial substances (lactic acid, diacetyl and hydrogen peroxide) at different concentrations in the minced meat samples with significant increases (p≤0.05) until the end of cold storage. Probiotics exhibited the ability to produce bacteriocins. Lactobacillus acidophilus as a probiotic showed a significant effect as bio-preservative against pathogens and was more effective when combined with Bifidobacterium BB12.