Evaluation of Adding Spirulina to Freeze-Dried Yogurts Before Fermentation and After Freeze-Drying

Improvement of growth and biochemical constituents of Rosmarinus officinalis by fermented Spirulina maxima biofertilizer

Delayed growth period and nature of woody stems are challenges for the urgent economic needs of rosemary plant culturing in the winter season. Different concentrations of biofertilizer initiated from Spirulina maxima, marine Lactobacillus plantarum, molasses and industrial organic waste (IOW) were subjected to freshly cut cuttings of the Rosmarinus officinalis L. (rosemary) plant to study the impact of this biofertilizer on the growth performance of the plant. The present work explored the potential of this biofertilizer in concentrations of 0.5%-1% and achieved a significant impact on the growth parameters and biochemical constituents of R. officinalis, a 27-day-old plant. The development of adventitious roots was earlier within one week, particularly at 0.5% and 1%. It can be concluded that the application of this biofertilizer at the lower concentrations enhanced the production of bioactive substances such as phytohormones (auxin, cytokinin, and gibberellins), carbohydrates, and vitamins; moreover, through controlling a range of physiological and biochemical processes, it can promote the intake of nutrients. Thus, this biofertilizer (Spirulina maxima, marine Lactobacillus plantarum, molasses and IOW) at a concentration of 1% is the recommended dose for application to agriculture sustainability.

Formulation and validation of probioticated foxtail millet laddu as a source of antioxidant for biological system using response surface methodology

Probiotics play a critical role in supporting a healthy gut microbiome, which significantly impacts overall health and well-being. While there has been an increase in the availability of probiotic foods in recent years, there may still be limited options and accessibility in certain regions. This study focused on formulating a traditional Indian sweet called laddu enriched with millet and Lactobacillus acidophilus. The formulation of laddu ingredients was optimized using Design Expert software to create an optimal product for testing. The probiotic Lactobacillus acidophilus culture was incorporated into the laddu in three forms: lyophilized, microencapsulated powder, and natural curd. The probiotic foxtail laddu was selected based on specific criteria such as color, odor, and texture. The nutritional analysis revealed that the laddu contained approximately 64.46 g of carbohydrates, 15.13 g of protein, and 5.06 g of fat per 100 g of laddu. A microbial count analysis was performed over a two-month storage period to assess the viability of the incorporated Lactobacillus acidophilus. The results showed that the lyophilized and microencapsulated culture demonstrated good viability, with counts of 6.10 ± 0.09 log CFU/g and 7.43 ± 0.02 log CFU/g, respectively, when stored at 4 °C. In comparison, storage at room temperature resulted in counts of 5.41 ± 0.08 log CFU/g and 6.97 ± 0.02 log CFU/g at the end of the storage period. Based on the findings, the probiotic millet laddu developed in this study has the potential to be a value-added food product that can enhance the overall health of consumers. Incorporating probiotics into traditional food items like laddu offers a convenient and enjoyable way to promote gut health and improve the product's nutritional value.

Volatile Compounds, Fatty Acids Constituents, and Antimicrobial Activity of Cultured Spirulina (Arthrospira fusiformis) Isolated from Lake Mariout in Egypt

In this study, Arthrospira fusiformis previously isolated from Lake Mariout (Alexandria, Egypt) was cultivated in the laboratory using a medium for pharmaceutical grade Arthrospira, named as Amara and Steinbüchel medium. Hot water extract of the Egyptian Spirulina was prepared by autoclaving dried biomass in distilled water at 121°C for 15 min. This algal water extract was analyzed by GC-MS to evaluate its volatile compounds and fatty acids composition. The antimicrobial activity of phycobiliprotein extract from Arthrospira fusiformis using phosphate buffer was evaluated against thirteen microbial strains (two Gram-positive bacteria, eight Gram-negative bacteria, one yeast, and two filamentous fungi). The major components of fatty acids in the hot extract of Egyptian A. fusiformis were hexadecanoic acid (palmitic acid, 55.19%) and octadecanoic acid (stearic acid, 27.14%). The main constituents of its volatile compounds were acetic acid (43.33%) and oxalic acid (47.98%). The most potent antimicrobial effect of phycobiliprotein extract was obtained against two Gram-negative bacteria Salmonella typhi and Proteus vulgaris, filamentous fungus Aspergillus niger, and the pathogenic yeast Candida albicans (all of which showed MIC values of 58.1 μg/ml). Escherichia coli and Salmonella typhimurium come second in their susceptibility to the phycobiliprotein extract from Arthrospira fusiformis and Serratia marcescens and Aspergillus flavus are the least in susceptibility, with MIC values of 116.2 and 232.5 μg/ml, respectively, while phycobiliprotein extract has no antibacterial effect on methicillin-resistant as well as susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Shigella sonnei. These findings confirmed the nutritional value of Egyptian A. fusiformis isolated from Lake Mariout and suggest the potential use of this strain as an ingredient in the cooking of some foods to increase the level of stearic acid and palmitic acid. Moreover, its effective antibacterial activities against some important and highly resistant to antibiotics bacterial pathogens in addition to its antifungal effects recommend the therapeutic use of its biomass.

Integration of Arthrospira platensis (spirulina) into the brewing process to develop new beers with unique sensory properties

Microalgae, and particularly the cyanobacterium Arthrospira platensis (spirulina), have attracted much attention due to their wide range of uses. The potential use of spirulina in food is mainly driven by its high content of macro and micronutrients including proteins, γ-linolenic acid, sulfated polysaccharides, minerals, vitamins, and the natural pigment phycocyanin. Despite these potential benefits, spirulina is still not widely used in the food industry due to numerous technological challenges during manufacturing or specific sensory issues in the final product. This research deals with the feasibility of integrating spirulina into the brewing process to create a tasty beer with high consumer acceptance. In the novel recipes, 5% (w/w) of the malt was replaced by spirulina powder. The first part of the study investigated inclusion at different time points throughout manufacturing of a reference beer style (mild pale ale). Compared to the control, alcoholic fermentation was slightly influenced by cyanobacterial biomass but resulted in a beer with a typical beer-like character. Sensory evaluations including a simple descriptive test, a popularity analysis, and Just-About-Right-Questions, indicated a complex alteration in the sensory properties. This includes a dominant algal taste that disturbs the character of the pale ale beers but also a deep blue color of the beer, if spirulina was included during the wort cooling phase. Based on these results, another set of beers with a higher original extract concentration and increased hop dosages was produced. These beers had a high popularity (6.0 original TESTSCORE; 7.12 and 6.64 optimized TESTSCORE), and also exhibited a deep blue color due to the natural pigment phycocyanin from spirulina. Further, bitterness and algal taste was rated by most of the panelists to be “just right” and the simple descriptive test indicated “sweetness” as important attribute which was not expected for this hoppy beer style.

Polysorbate 80 improves the adhesion and survival of yogurt starters with cholesterol uptake abilities

The goal of this study is to improve the adhesion and survival of yogurt bacteria with probiotic traits by using polysorbate 80, a food additive emulsifier commonly found in milk derivative products. Polysorbate 80 was used at 1% (w/v), and its effects on yogurt bacteria's survival under simulated digestive conditions, cholesterol uptake activities, bile salt hydrolase (BSH) activity, and adhesion to HT-29 culture were studied. In the presence of 1% polysorbate 80, both starters demonstrated better cholesterol uptake and BSH activities, as well as higher bacterial survival at pH 2.5, particularly in associated cultures. In the presence of 0.3 % bile or cholic acid, polysorbate 80 reduced the drop in L. bulgaricus's survival load. However, the carbon source had a greater impact on S. thermophilus bile tolerance than the food additive emulsifier. Oleic acid was incorporated into both bacterial membranes when grown in the presence of bile and polysorbate 80, resulting in a higher unsaturated/saturated fatty acid ratio. In the presence of polysorbate 80, S. thermophilus adhered to HT-29 cells 2.3-fold better, while L. bulgaricus's adhesion remained unchanged. We suggest that polysorbate 80 may have a protective effect on cell survival under simulated digestive stress as well as a role in yogurt bacteria adhesion to the intestines, giving these bacteria more opportunities to exert their purported cholesterol-removal activities.

Microalgae as source of functional ingredients in new-generation foods: challenges, technological effects, biological activity, and regulatory issues

Microalgae feasibility as food ingredients or source of nutrients and/or bioactive compounds and their health effects have been widely studied. This review aims to provide an overview of the use of microalgae biomass in food products, the technological effects of its incorporation, and their use as a source of health-promoting bioactive compounds. In addition, it presents the regulatory aspects of commercialization and consumption, and the main trends and market challenges Microalgae have stood out as sources of nutritional compounds (polysaccharides, proteins, lipids, vitamins, minerals, and dietary fiber) and biologically active compounds (asthaxanthin, β-carotene, omega-3 fatty acids). The consumption of microalgae biomass proved to have several health effects, such as hypoglycemic activity, gastroprotective and anti-steatotic properties, improvements in neurobehavioral and cognitive dysfunction, and hypolipidemic properties. Its addition to food products can improve the nutritional value, aroma profile, and technological properties, with important alterations on the syneresis of yogurts, meltability in cheeses, overrun values and melting point in ice creams, physical properties and mechanical characteristics in crisps, and texture, cooking and color characteristics in pastas. However, more studies are needed to prove the health effects in humans, expand the market size, reduce the cost of production, and tighter constraints related to regulations.

Solid-State Fermentation of Arthrospira platensis to Implement New Food Products: Evaluation of Stabilization Treatments and Bacterial Growth on the Volatile Fraction

Arthrospira platensis is a cyanobacterium widely used in food formulation and mainly consumed as a food supplement because of its high amount of proteins, vitamins and minerals. Different probiotic food supplements are present in the market, and a lactic acid fermented food product like dried spirulina could be useful not only to introduce lactic acid bacteria (LAB) with beneficial effects to the diet of consumers, but also to improve or change the aromatic profile of the substrate. Therefore, the aim of this study was the evaluation of lactic acid fermentation of A. platensis biomass, focusing on the consequent changes in the aromatic profile. For this purpose, two different stabilization treatments (UV light treatment and sterilization) were applied prior to fermentation with two LAB strains, Lacticaseibacillus casei 2240 and Lacticaseibacillus rhamnosus GG. The biomass proved to be a suitable matrix for solid-state fermentation, showing a LAB growth of more than 2 log CFU/g in 48 h. The fermentation process was also useful for off-flavor reduction. In particular, the fermentation process significantly influenced the concentration of those compounds responsible for aldehydic/ethereal, buttery/waxy (acetoin and diacetyl), alkane and fermented aromatic notes (isoamyl alcohol). The heat treatment of the matrix, in addition to guaranteed safety for consumers, led to an improved aroma after fermentation. In conclusion, a fermented spirulina powder with a different aromatic profile was obtained with the applied heat treatment. Fermentation with lactic acid bacteria can be an interesting tool to obtain cyanobacterial biomasses with more pleasant sensory properties for potential use in food formulations.

Lactic Acid Fermentation of Arthrospira platensis (Spirulina) in a Vegetal Soybean Drink for Developing New Functional Lactose-Free Beverages

The main objective of this study was to evaluate the suitability of Arthrospira platensis F&M-C256 (spirulina) biomass in a vegetal soybean drink or in water, as substrate for lactic acid fermentation by the probiotic bacterium Lactiplantibacillus plantarum ATCC 8014 (LAB8014) and to evaluate the fermented products in terms of bacteria content and organic acids content, biochemical composition, total phenolics, and phycocyanin content, in vitro digestibility, in vitro and in vivo antioxidant activity. After 72 h of fermentation, a bacterial concentration of about 10.5 log CFU mL^–1 in the broths containing the soybean drink + spirulina + LAB8014 (SD + S + LAB8014) or water + spirulina + LAB8014 (W + S + LAB8014) was found. Lactic acid concentration reached similar values (about 1.7 g L^–1) in the two broths, while a different acetic acid concentration between SD + S + LAB8014 and W + S + LAB8014 broths was observed (7.7 and 4.1 g L^–1, respectively). A. platensis biomass was shown to be a suitable substrate for LAB8014 growth. After fermentation, both broths contained a high protein content (>50%). In both broths, total phenolics, in vitro and in vivo antioxidant activity increased after fermentation (+35, +20, and +93% on average, respectively), while phycocyanin content decreased (−40% on average). Digestibility of W + S + LAB8014 broth statistically improved after fermentation. This study highlights the potential of A. platensis F&M-C256 biomass as a substrate for the production of new functional lactose-free beverages.

Edible Seaweeds and Spirulina Extracts for Food Application: In Vitro and In Situ Evaluation of Antimicrobial Activity towards Foodborne Pathogenic Bacteria

Research is more and more focused on studying and selecting food preservatives of natural origin. In this scenario, algae are an excellent source of bioactive compounds, among which are antimicrobials, whose presence is variable depending on the algal species and environmental conditions. The aim of the present study was to obtain, by a food grade approach, antimicrobial extracts from five species already approved as foods and to test their efficacy in vitro (agar well diffusion assay) and in situ (microbial challenge test) towards foodborne pathogenic bacteria. Moreover, the total phenolic compounds of the extracts were determined in order to evaluate possible correlations with the antimicrobial activity. Strains belonging to Salmonella spp., Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus were considered. Overall, the extracts showed a good antimicrobial activity in vitro towards all the tested microorganisms, especially L. monocytogenes (15 mm of inhibition diameter). The effect of inhibition was monitored during 24, 48 and 120 h showing a good persistence in time. Arthrospira platensis exerted the highest efficacy, further revealed towards L. monocytogenes on salmon tartare as bacteriostatic using 0.45% of the extract and bactericidal using 0.90%. The presence of phenolic compounds could be related to the antimicrobial activity but was not revealed as the main component of this activity. The extract with the highest phenolic content (18.79 ± 1.90 mg GAE/g) was obtained from Himanthalia elongata. The efficacy, confirmed also in a food matrix, might open perspectives for their application as food preservative.

Arthrospira platensis as Natural Fermentation Booster for Milk and Soy Fermented Beverages

Arthrospira platensis, commercially known as Spirulina, is a fresh-water cyanobacterium that has been gaining increasing attention in recent years due to its high biological and nutritional value. For this reason, it has been employed in several food applications, to obtain or enhance functional and technological properties of cheese, yogurt, bread, cookies or pasta. The aim of this work was to evaluate the potential boosting effect of two different concentrations (0.25% and 0.50% w/v) of A. platensis on the fermentation capability of several starter lactic acid bacteria (LAB) strains, 1 probiotic and 4 commercial mix culture. These strains were used to ferment three different substrates and their fermentation behaviors were evaluated by impedance analyses together with rheological and color measurements. In tryptic soy broth (TSB), the A. platensis boosting effect was significantly higher if compared to yeast extract for all the starter LAB strains except for Lb. casei, which was equally stimulated. Different results were found when the same LAB strains were cultivated in SSM. The most evident boosting effect was found for S. thermophilus and Lb. casei. LAB growth was promoted by A. platensis, confirming that it could be a useful tool in the production of novel functional fermented dairy foods. The potential boosting effect was evaluated on four commercial mix cultures used to produce milk and soy fermented beverages. It was demonstrated that the booster effect took place, but it was variable and dependent not only on the mix culture used, but also on the substrate and A. platensis concentration. Also, rheological and color modifications were found to be dependent on these factors.