Bacterial Fibrinolytic Enzyme Coding Sequences from Indonesian Traditional Fermented Foods Isolated Using Metagenomic Approach and Their Expression in Escherichia Coli

Fibrinolytic proteins play an important role in treatment of cardiovascular disease. This study aimed to express coding sequences of new bacterial fibrinolytic protein from Indonesian traditional fermented foods obtained by a PCR-based metagenomic approach and to test their biological activity. New amino acid variations were found in nattokinase (NAT) at several positions i.e. D41N and V192A from dried Tauco, V4F, D41N, and V192A from yellow Oncom but not in Douchy Fibrinolytic Enzyme (DFE) from Terasi. The NAT and DFE recombinant versions were overproduced in Escherichia coli BL21(DE3) using pET16b(+). Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis analysis showed all clones produced mature soluble fibrinolytic proteins of 28 kDa. All recombinant proteins displayed caseinolytic and fibrinolytic activities. In conclusion, metagenomic approach can be applied to obtain and to express coding sequences of new variant bacterial fibrinolytic protein as active soluble mature form in E. coli.     

Cold plasma processing of milk and dairy products

BackgroundThermal pasteurization and sterilization are predominantly used in the dairy industry due to their efficacy in improving the product safety and shelf life. However, heat treatment can cause undesirable protein denaturation, non-enzymatic browning, loss of vitamins and volatile flavor compounds, freezing point depression, and flavour changes. Cold plasma is a non-thermal technology that has gained attention in recent years as a potential alternative method for chemical and thermal disinfection in foods using ambient or moderate temperatures and short treatment times.Scope and approachThis review aims to describe the fundamentals, parameters, and technology on cold plasma, discussing the critical processing factors involved in this technology. Also, it describes the mechanisms of microbial inactivation and provides an overview of the effects of non-thermal plasma on the quality of dairy products, considering a physicochemical, sensory and microbiology perspective.Key findings and conclusionsCold plasma uses less aggressive mechanisms of action to the milk matrix when compared to the techniques currently used, and has shown an excellent performance on the elimination of pathogenic and spoilage microorganisms besides maintaining, in many cases, the nutritional, functional, and sensory characteristics of the product.     

Characterisation of oleoresins extracted from tomato waste by liquid and supercritical carbon dioxide

Tomato waste is characterised by high amounts of bioactive compounds, such as carotenoids, polyphenols and essential fatty acids. In this work, oleoresins were produced from tomato waste (skins + seeds) and skins using carbon dioxide under liquid and supercritical conditions. The use of ethanol as a co-solvent was also evaluated. Compositions of the oleoresins were analysed and compared to oleoresin obtained by means of an organic solvent, which was used as the control. Oleoresin extraction from the waste by liquid and supercritical CO₂ provided the highest yields (12.5%–12.9%). The extracts obtained from the skins with supercritical CO₂ without ethanol had the highest content of α- and γ-tocopherols (80 and 575 mg/100 g oleoresin, respectively), while lycopene and β-carotene were found at 205 and 75 mg/100 g oleoresin, respectively. The highest quantity of polyphenols (9305 mg GAE/100 g oleoresin) was found in the oleoresin extracted from skin by supercritical CO₂ with ethanol. All oleoresins were characterised by a high antioxidant activity, which improved with the synergy of carotenoids, tocopherols and polyphenols.     

Lactic fermentation of cooked navy beans by Lactobacillus paracasei CBA L74 aimed at a potential production of functional legume-based foods

In recent years, scientific interest in the development of non-dairy-based functional foods is increasing progressively and the fermentation of cereals, legumes, fruits and vegetable-based foods is becoming an important scientific research topic for the production of new probiotic products. In particular, legumes represent a possible alternative to protein foods from animal origins and an adequate fermentation substrate as they contain high amount of nutrients, such as proteins, carbohydrates, fibres, vitamins, and minerals, which are all useful to the growth and metabolic activity of certain microorganisms. This work focuses on the feasibility of developing a dry legume-based functional product using a fermentation process carried out on a 10% w/v navy bean suspension, in a lab-scale stirred batch reactor. After soaking and cooking dried navy beans, the fermentation tests performed on the resulting medium using Lactobacillus paracasei CBA L74 showed a maximum bacterial count of 10⁹ CFU/mL after 20 hours and a maximum lactic acid concentration of 1.9 g/L after 16 hours of process time. A freeze-drying process was performed on the fermented bean suspension, showing a 2-log microbial reduction and a bacterial viability in the resulting probiotic powder of 3.7 × 10⁸ CFU/g.     

Ensuring the future of functional foods

Consumption of functional foods suggests a strategy to reduce the incidence of chronic health disorders. This message has resonated with consumers and driven market growth. Functional food research has significantly increased over the last decade but few studies have addressed the bioavailability of active ingredients for clinical efficacy. Baked goods such as bread, biscuits and cake are popular categories for innovation due to their widespread consumption. These new developments have often impacted on organoleptic properties of the finished products and thus consumer acceptance. Blending of bioactive ingredients may overcome this deficit. However, an understanding of the role of the microbiome in health has indicated that the efficacy of functional foods is unlikely to be uniform within the population. Further growth in the functional foods market, is likely to require greater evidence of the bioavailability of active ingredients, clinical effect and support for health claims by regulators especially in the EU.     

Understanding stickiness in sugar-rich food systems: A review of mechanisms,analyses, and solutions of adhesion

Stickinessis an inherent textural property in many sugar-rich foods, which can be problematic to the processing of confectionery products. The adhesion between foods and contact surfaces during processing and consumption has not been well understood in academia or industry. The theories of adhesion were discovered by scientists in the adhesive field of study, some of which can explain the stickiness phenomenon of confections. This work reviewed these theories in the context of sugar-rich foods, followed by a survey on the sensory and instrumental analyses of stickiness. Furthermore, the contributions of ingredients, temperature, compression, and contact surfaces to sugar-rich food adhesion are highlighted.     

Sweet processed foods in Brazil: use of sugar and sweeteners,inclusion of sugar claims and impact on nutritional profile

This study characterised the main sweet beverages and food products marketed in Brazil regarding (i) the addition of sugar/sweeteners, (ii) nutritional profile and (iii) sugar claims. Results revealed that most of the beverages had added sweeteners, while food products were mainly sweetened with sugar. Moreover, >90% of the powdered products had added sweeteners. ‘Zero sugar’ (46%) and ‘light’ (55%) were the most common sugar claims in sugar-free and reduced-sugar products, respectively. Powdered products, soya drinks and baked products included claims less frequently. Regarding the nutritional profile, beverages with sugar substitution had a proportionally greater reduction in the content of carbohydrates and calories (up to 99%, for both) in relation to food (<82% and <85%, respectively). The results suggest that reducing sugar in solid foods remains a greater challenge than in beverages and that this reduction has less impact on the final energy density of foods.     

Development of vitamin E-enriched functional foods: stability of tocotrienols in food systems

Tocotrienols are members of the vitamin E family that provide many nutritional benefits. Developing tocotrienol-fortified functional foods introduces vitamin E into consumers diets without changing their food habits. The purpose of this study was to compare the stability of tocotrienols in bulk form and six food matrices at a fixed dose (40 mg kg⁻¹) under accelerated and conventional storage conditions. The delta- and gamma-tocotrienol content was measured using HPLC, and the sensory attributes were evaluated using triangle and hedonic tests. Tocotrienol in bulk powder was less stable under stressed conditions than in bulk oil, with the powders having approximately 40% and 80% reduction in δ- and γ- after storage and bulk oil with no significant degradation. HPLC analysis demonstrated that tocotrienol content remained unchanged in dry mix lemonade, yogurt, raw and UHT milk, and margarine over time; however, complete degradation of γ- and partial degradation (up to 50%) of δ-tocotrienol was observed in bread during ambient and stressed storage conditions. A significant decrease in the δ-tocotrienol relative concentration was also observed in HTST processed milk samples. Tocotrienol addition was not perceived, and no significant difference in the product attributes and overall liking was reported in the discrimination sensory testing.