Determination of prebiotic activity and probiotic encapsulation ability of inulin type fructans obtained from Inula helenium roots

Inulin, a prebiotic utilized in the food and pharmaceutical industries, promotes the growth of beneficial bacteria in the colon, thereby enhancing human health. Although inulin is commercially produced from chicory and artichoke, Inula helenium roots offer a high potential for inulin production. The aim of this study is to investigate the prebiotic activity of inulin (inulin-P) from I. helenium roots on Lactobacillus rhamnosus, as well as its ability to produce synbiotic microcapsules and the effects on probiotic viability during freeze-drying, in vitro gastrointestinal (GI) digestion, and storage. First, the effect of inulin-P on L. rhamnosus viability and short-chain fatty acid (SCFA) production was compared to other commonly utilized prebiotics. The findings revealed that inulin-P remarkably promoted the growth and SCFA yield of L. rhamnosus for 48 h of fermentation and 28 days of storage. Then, L. rhamnosus was encapsulated with inulin-P and commercial inulin to compare its survival throughout storage and the GI tract. Inulin-P microcapsules outperformed in terms of viability during storage (7.98 log CFU/g after 30 days at 4°C). Furthermore, inulin-P microcapsules were heat-resistant and protected L. rhamnosus from GI conditions, resulting in a high survival rate (89.52%) following large intestine simulation, which is ideal for increasing customer benefits. Additionally, inulin-P microcapsules exhibited similar physical characteristics to commercial inulin. Consequently, this study revealed that inulin-P, which is easy to produce, low-cost, and has industrial application potential, could be used as a good carrier for the synbiotic encapsulation of L. rhamnosus. PRACTICAL APPLICATION: Inulin is a prebiotic that promotes the activity and growth of beneficial bacteria in the human gut. Although commercial inulin is currently produced from chicory root and artichoke, Inula helenium root is a potential raw material for inulin production. In this study, inulin was produced from I. helenium roots with a low-cost and easy production method, and it was determined that this inulin was an effective carrier in the synbiotic encapsulation of L. rhamnosus. This inulin exhibits superior prebiotic activity and encapsulation efficiency compared to commercial inulins like Orafti® GR and HPX and can be easily integrated into industrial production.

Bigel Matrix Loaded with Probiotic Bacteria and Prebiotic Dietary Fibers from Berry Pomace Suitable for the Development of Probiotic Butter Spread Product

This study presents a novel approach to developing a probiotic butter spread product. We evaluated the prebiotic activity of soluble dietary fibers extracted from cranberry and sea buckthorn berry pomace with different probiotic strains (Limosilactobacillus reuteri, Lacticaseibacillus paracasei, and Lactiplantibacillus plantarum), uploaded selected compatible combination in the bigel matrix, and applied it in the probiotic butter spread formulation. Bigels and products were characterized by physical stability, rheological, textural properties, and viability of probiotics during storage at different conditions. The highest prebiotic activity score was observed in soluble cranberry (1.214 ± 0.029) and sea buckthorn (1.035 ± 0.009) fibers when cultivated with L. reuteri. The bigels loaded with probiotics and prebiotic fiber exhibited a significant increase in viscosity (higher consistency coefficient 40-45 Pa·sn) and better probiotic viability (>6 log CFU/g) during long-term storage at +4 °C temperature, surpassing the bigels loaded with probiotics alone. Bigels stored at a lower temperature (-18 °C) maintained high bacterial viability (above 8.5 log CFU/g). The butter spread enriched with the bigel matrix was softer (7.6-14.2 N), indicating improved spreadability. The butter spread product consistently met the required 6 log CFU/g for a functional probiotic food product until 60 days of storage at +4 °C temperature. The butter stored at -18 °C remained probiotic throughout the entire storage period, confirming the protective effect of the bigel matrix. The study's results showed the potential of the bigel to co-encapsulate, protect, and deliver probiotics during prolonged storage under different conditions.

Effect of Malva neglecta and lactulose on survival of Lactobacillus fermentum and textural properties of synbiotic stirred yogurt

Yogurt is a popular dairy product and its consumption has been progressively growing over the past few decades by raising consumers' health-consciousness. As yogurt is growing in popularity, manufacturers are continuously seeking for bioactive components such as probiotics and prebiotics, to produce functional yogurt with more beneficial health effects. Therefore, this study aimed to evaluate the effect of Malva neglecta (MN, 0, 5, 10 and 15%) and lactulose (0, 1 and 2%) as prebiotic substances on survival of Lactobacillus fermentum in a half-fat synbiotic stirred yogurt. The results revealed that with increasing MN and lactulose concentrations, the count of Lb. fermentum significantly increased (p < 0.05). At the end of 21-day cold storage, the count of probiotics in yogurt sample having 2% lactulose and 10-15% MN significantly was higher than control (8.37-8.4 vs. 7.73 Log cfu/g). With increasing the amount of MN and lactulose, firmness and chewiness of yogurt samples decreased while adhesiveness increased (p < 0.05). Scanning electron microscopy assessment shown that addition of MN and lactulose resulted in a higher moisture retention in the void spaces. The results revealed that by incorporating lactulose and MN in yogurt formulation, an appropriate synbiotic yogurt could be produced as a novel functional product.

Profile of Volatile Compounds in Dessert Yogurts Prepared from Cow and Goat Milk, Using Different Starter Cultures and Probiotics

The purpose of this study was to determine the profile of volatile compounds (aroma) and overall flavor in dessert yogurts prepared from cow and goat milk, using three different, commercially available starter cultures, in the presence or absence of probiotic bacteria and to correlate this to organoleptic evaluation results obtained using a consumer acceptability method. The extraction of volatile compounds was carried out by solid phase micro-extraction; separation and analysis by gas chromatography-mass spectrometry. Variations among the different classes of compounds (i.e., aldehydes, alcohols, ketones, volatile acids, hydrocarbons, and terpenes) were recorded for different treatments. The results showed that the main volatiles in the cow milk dessert yogurts without Bifidobacterium BB-12 were: acetaldehyde, 2,3-butanedione, 2,3-pentanedione, 3-OH-2-butanone, 2-propanone, hexanoic acid and limonene). Respective volatiles in cow milk dessert yogurts with Bifidobacterium BB-12 were: acetaldehyde, pentanal, hexanal, the same ketones, acetic acid and limonene). The volatiles in goat milk dessert yogurts without Lactobacillus acidophilus LA-5 were: acetaldehyde, the same ketones, no carboxylic acids, limonene, camphene, α- and β-pinene. Respective volatiles in goat milk dessert yogurts with Lactobacillus acidophilus LA-5 were: aldehydes acetaldehyde, the same ketones, butanoic acid, α-pinene and camphene varying in concentration in different samples. Based on the results of volatiles and organoleptic evaluation, it can be concluded that dessert yogurts from cow milk without probiotic bacterial strains using the mild and classic starter cultures, and dessert yogurts from goat milk with probiotic bacterial strains using the classic and acidic starter cultures are found to be more organoleptically acceptable by consumers. In most cases, a positive correlation was found between dessert yogurt organoleptically determined flavor and volatiles (aldehydes, ketones and carboxylic acids).

Rice straw and orange peel wastes as cheap and eco-friendly substrates: A new approach in β-galactosidase (lactase) enzyme production by the new isolate L. paracasei MK852178 to produce low-lactose yogurt for lactose-intolerant people

Converting wastes to valuable products is the main target for many kinds of research nowadays. Wastes represent an environmental problem and getting rid of it is not easy and causes pollution. Accordingly, this study offers production of the valuable enzyme β-galactosidase using rice straw and orange peel as the main medium constituents. β-galactosidase converts lactose to glucose and galactose which are simple sugars and can be fermented easily by lactose-intolerant people who represent more than 50% of the world's population. It was produced by Lactobacillus paracasei, a series isolated from fermented milk, identified using 16S ribosomal RNA gene partial sequence and had the accession number MK852178. Plackett-Burman (PB) and Central Composite (CCD) Designs optimized the production scoring 1.683(10)⁶ U/ml with a difference five times higher than the non-optimized medium. The addition of 0.3 or 0.6% of β-galactosidase serves as a good fortification for manufacturing nutritional and therapeutic low-lactose yogurt with no significant differences in total protein, total solids, fat, and ash between control and all treatments. The chemical, rheological and sensory properties of the final produced yogurt were evaluated during storage periods up to 9 days at 5 °C. In conclusion, L. paracasei MK852178 β-galactosidase is a promising additive in manufacturing low lactose yogurt for lactose-intolerant people since it reduces the lactose content and doesn't influence the chemical and sensory properties.

Probiotics in the dairy industry-Advances and opportunities

The past two decades have witnessed a global surge in the application of probiotics as functional ingredients in food, animal feed, and pharmaceutical products. Among food industries, the dairy industry is the largest sector where probiotics are employed in a number of dairy products including sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula. These probiotics are either used as starter culture alone or in combination with traditional starters, or incorporated into dairy products following fermentation, where their presence imparts many functional characteristics to the product (for instance, improved aroma, taste, and textural characteristics), in addition to conferring many health-promoting properties. However, there are still many challenges related to the stability and functionality of probiotics in dairy products. This review highlights the advances, opportunities, and challenges of application of probiotics in dairy industries. Benefits imparted by probiotics to dairy products including their role in physicochemical characteristics and nutritional properties (clinical and functional perspective) are also discussed. We transcend the traditional concept of the application of probiotics in dairy products and discuss paraprobiotics and postbiotics as a newly emerged concept in the field of probiotics in a particular relation to the dairy industry. Some potential applications of paraprobiotics and postbiotics in dairy products as functional ingredients for the development of functional dairy products with health-promoting properties are briefly elucidated.

Co-encapsulation of probiotics with prebiotics and their application in functional/synbiotic dairy products

Oral administration of live probiotics along with prebiotics has been suggested with numerous beneficial effects for several conditions including certain infectious disorders, diarrheal illnesses, some inflammatory bowel diseases, and most recently, irritable bowel syndrome. Though, delivery of such viable bacteria to the host intestine is a major challenge, due to the poor survival of the ingested probiotic bacteria during the gastric transit, especially within the stomach where the pH is highly acidic. Although microencapsulation has been known as a promising approach for improving the viability of probiotics in the human digestive tract, the success rate is not satisfactory. For this reason, co-encapsulation of probiotics with probiotics has been practised as a novel alternative approach for further improvement of the oral delivery of viable probiotics toward their targeted release in the host intestine. This paper discusses the co-encapsulation technologies used for delivery of probiotics toward better stability and viability, as well the incorporation of co-encapsulated probiotics and prebiotics in functional/synbiotic dairy foods. The common encapsulation technologies (and the materials) used for this purpose, the stability and survival of co-encapsulated probiotics in the food, and the release behavior of the co-encapsulated probiotics in the gastrointestinal tract have also been explained. Most studies reported a significant improvement particularly in the viability of bacteria associated with the presence of prebiotics. Nevertheless, the previous research has mostly been carried out in the simulated digestion, meaning that future systematic research is to be carried out to investigate the efficacy of the co-encapsulation on the survival of the bacteria in the gut in vivo.

A Comprehensive Study of the Impacts of Oat β-Glucan and Bacterial Curdlan on the Activity of Commercial Starter Culture in Yogurt

This study provides important information about the impacts of various levels of oat (OBG) and bacterial (curdlan) β-glucan and fat contents in milk on survivability and metabolism of yogurt starter cultures. The results show that addition of β-glucans in the concentration higher than 0.25% reduced starter bacterial counts during storage and prolonged the milk acidification process. A significant increase in lactose consumption by starter cultures was noted in the yogurt samples with OBG addition up to 0.75%. The highest (by 567% on average) increase in lactic acid content was noted in the control yogurts. Whereas the lowest (by 351%) increase in lactic acid content was noted in yogurts with OBG. After 28-day storage, the acetic aldehyde content was significantly influenced by fat content, type and addition level of polysaccharide. A higher increase in acetoin content was noted in samples with 0.25% than in samples with 1% of polysaccharides. In turn, significantly lower increases in diacetyl and 2,3-pentanedione contents were observed in the yogurt samples with OBG than in these with curdlan, with diacetyl production increase along with the higher concentration of the polysaccharide. The addition of OBG and curdlan to milk contributed to differences in the starter culture metabolism, consequently, in the milk acidification dynamics.

Traditional plain yogurt: a therapeutic food for metabolic syndrome?

Dairy products have an important role in a healthy diet due to their high-quality protein and rich micronutrients. Yogurt, a fermented milk product, has a similar composition to milk but is a more concentrated product in terms of group B vitamins, minerals, and proteins. It is known that bioactive metabolites and live enzymes that occur by fermentation and digestion, affect the health positively by improving gut microbiota. In recent years, the prevalence of metabolic syndrome, which threatens public health, is increasing rapidly. As with other noninfectious diseases, the diet has an important effect on the prevention and treatment of metabolic syndrome. It has been demonstrated that yogurt has a high-quality amino acid pattern, reduces energy intake by stimulating satiety, and regulates blood glucose level. In addition to the rich protein variety, yogurt also contains peptides that positively affect blood pressure. Unlike milk, increased acidity during the fermentation of yogurt positively affects calcium absorption. Calcium plays an important role in the control of blood glucose and energy metabolism through insulin-dependent and non-insulin-dependent routes. In addition to reducing inflammation, calcium has a positive effect on the regulation of the blood lipid profile by increasing fecal fat excretion. There are many lipid and lipoid nutrients such as saturated fatty acids, phospholipids, sphingolipids, and conjugated linoleic acid that may affect the blood lipid profile in yogurt positively or negatively. There are seen very few randomized controlled studies that are focused on the relationship between yogurt and metabolic syndrome, and these are based on contradictory results. In this review, based on the clinical studies conducted to date, and the nutrient content of yogurt, possible mechanisms of these contradictory results are investigated.

Impact of Milk Fortification on the Microbiological and Physicochemical Properties of Set-Type Skimmed Yoghurt Using Three Commercial Soluble Prebiotics

The impact of milk fortification on the microbiological and physicochemical properties of a set-type skimmed yoghurt using three commercial soluble prebiotics (inulin, iso-malto-oligosaccharides, and xylo-oligosaccharides) at either 3 or 5 g/kg was assessed. The three prebiotics had an insignificant impact on yoghurt fermentation because all yoghurt samples had similar titratable acidity and similar pH values after their lactic acid fermentation. Regarding the control yoghurt samples without prebiotics usage, the prebiotics-fortified yoghurt samples showed no difference in their main chemical compositions, hardness, syneresis extent, and apparent viscosity (p > 0.05), but had a slightly higher lactic acid content and a viable quantity of starter strains. All yoghurt samples had the same acetic acid content, while propionic and butyric acids were not produced. Yoghurt storage at 4 C for 21 d gave these yoghurt samples decreased pH values and a viable quantity of starter strains (especially Lactobacillus delbrueckii subsp. bulgaricus) and unchanged acetic acid; however, it increased lactic acid contents. Overall, prebiotics fortification up to 5 g/kg had a completely insignificant impact on the fermentation and quality attributes of yoghurt samples but could possibly improve the health of consumers due to higher dietary fibers and starter strain populations.

Use of β-glucan from spent brewer's yeast as a thickener in skimmed yogurt: Physicochemical, textural, and structural properties related to sensory perception

Powdered β-glucan extracted from brewer's yeast (Yestimun, Leiber GmbH, Bramsche, Germany) was incorporated into skimmed-milk yogurt at varying concentrations (0.2-0.8% wt/wt) to investigate its potential application as a thickener. The effect of β-glucan fortification on the nutritional profile, microstructure, physicochemical properties, and texture of freshly prepared yogurts was investigated. Sensory evaluation was also conducted and was correlated with instrumental analysis. The addition of Yestimun significantly reduced the fermentation time of the yogurt mix from 4 h to 3 h. Scanning electron microscopy revealed that β-glucan particles formed small spherical clusters within the yogurt matrix. The majority of the physicochemical properties (syneresis, viscosity, color, and titratable acidity) remained unaffected by the incorporation of Yestimun in the recipe. Textural properties showed a gradual increment with increasing β-glucan concentration. Hardness, total work done, adhesive force, and adhesiveness increased by 19.27, 23.3, 21.53, and 20.76%, respectively, when using the highest amount of Yestimun powder. Sensory analysis (n = 40) indicated that fortifying yogurt with Yestimun at 0.8% (wt/wt) concentration may affect overall acceptance ratings, which was attributed to adverse flavor and aftertaste effects. However, the overall liking score of the yogurt (5.0/9.0) shows potential for commercialization of the product.

Influence of commercial inactivated yeast derivatives on the survival of probiotic bacterium Lactobacillus rhamnosus HN001 in an acidic environment

This study evaluated the influence of three inactivated yeast derivatives (IYDs) used in wine production, namely OptiRed^®, OptiWhite^® and Noblesse^®, on the viability of the probiotic strain Lactobacillus rhamnosus HN001 in an acidic environment. Addition of the IYDs at 3 g/L significantly enhanced the survival of the probiotic bacteria by 2.75–4.05 log cycles after 10-h exposure in a pH 3.0 buffer. Acid stress assay with IYD components obtained after centrifugation and filtration revealed that water-soluble compounds were responsible for improving the acid tolerance of L. rhamnosus HN001 for all three preparations. Differences in protective effect amongst the IYDs on L. rhamnosus HN001 were observed when permeates and retentates of the water-soluble extracts, obtained through ultrafiltration with a 2 kDa membrane, were assayed against the lactic acid bacterium. Chemical analysis of the water-soluble components suggests that low molecular weight polysaccharides, specific free amino acids and/or antioxidants in the 2 kDa permeates could have contributed to the enhanced survival of L. rhamnosus HN001 during acid stress. The contrast amongst the 2 kDa retentates’ viability enhancing property may have been attributed to the differences in size and structure of the higher molecular weight carbohydrates and proteins, as the survival of the probiotic did not relate to the concentration of these compounds. These results suggests that oenological IYDs could potentially be applied to probiotic foods for enhancing the acid tolerance of the beneficial microorganisms, and consequently prolonging the shelf life of these products.

Growth and acid production of Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 in the fermentation of algal carcass

Algal carcass is a low-value byproduct of algae after its conversion to biodiesel. Dried algal carcass is rich in protein, carbohydrate, and multiple amino acids, and it is typically well suited for growth and acid production of lactic acid bacteria. In this study, Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 was used to ferment different algal carcass media (ACM), including 2% ACM, 2% ACM with 1.9% glucose (ACM-G), and 2% ACM with 1.9% glucose and 2g/L amino acid mixture (ACM-GA). Concentrations of organic acids (lactic acid and acetic acid), acetyl-CoA, and ATP were analyzed by HPLC, and activities of lactate dehydrogenase (LDH), acetokinase (ACK), pyruvate kinase (PK), and phosphofructokinase (PFK) were determined by using a chemical approach. The growth of L. bulgaricus cells in ACM-GA was close to that in the control medium (de Man, Rogosa, and Sharpe). Lactic acid and acetic acid contents were greatly reduced when L. bulgaricus cells were grown in ACM compared with the control medium. Acetyl-CoA content varied with organic acid content and was increased in cells grown in different ACM compared with the control medium. The ATP content of L. bulgaricus cells in ACM was reduced compared with that of cells grown in the control medium. Activities of PFK and ACK of L. bulgaricus cells grown in ACM were higher and those of PK and LDH were lower compared with the control. Thus, ACM rich in nutrients may serve as an excellent substrate for growth by lactic acid bacteria, and addition of appropriate amounts of glucose and amino acids can improve growth and acid production.

Prebiotic potential of gum odina and its impact on gut ecology: in vitro and in vivo assessments

The attributed effects of gum odina as a novel prebiotic and immunomodulatory agent are studied.

Lyophilised Vegetal BM 297 ATO-Inulin lipid-based synbiotic microparticles containing Bifidobacterium longum LMG 13197: design and characterisation

This study aimed at the manufacturing and characterisation of Vegetal BM 297 ATO-inulin-Bifidobacterium longum LMG 13197 microparticles prepared by freeze drying. Emulsions containing 1%, 1.5%, 2%, 3.5% or 5% w/v inulin were prepared, with or without centrifugation before freeze drying. Morphological properties, particle size distribution, encapsulation efficiency of the microparticles and their ability to preserve viability of the enclosed B. longum LMG 13197 cells were evaluated. The microparticles produced from both formulations without a centrifugation step were irregular, porous with concavities and contained high number of bacterial cells. Formulations with or without inulin had average particle sizes of 33.4-81.0 μm with encapsulation efficiencies of 82% and 88%, respectively. Vegetal-inulin microparticles have the morphology and size that will enable their even distribution in final food products, and hence, they have the potential for use as a functional food additive because they are likely to deliver sufficient numbers of viable bacteria.

Galacto-oligosaccharides and Colorectal Cancer: Feeding our Intestinal Probiome

Prebiotics are ingredients selectively fermented by the intestinal microbiota that promote changes in the microbial community structure and/or their metabolism, conferring health benefits to the host. Studies show that β (1-4) galacto-oligosaccharides [β (1-4) GOS], lactulose and fructo-oligosaccharides increase intestinal concentration of lactate and short chain fatty acids, and stool frequency and weight, and they decrease fecal concentration of secondary bile acids, fecal pH, and nitroreductase and β-glucuronidase activities suggesting a clear role in colorectal cancer (CRC) prevention. This review summarizes research on prebiotics bioassimilation, specifically β (1-4) GOS, and their potential role in CRC. We also evaluate research that show that the impact of prebiotics on host physiology can be direct or through modulation of the gut intestinal microbiome, specifically the probiome (autochtonous beneficial bacteria), we present studies on a potential role in CRC progression to finally describe the current state of β (1-4) GOS generation for industrial production.

Proteolytic and ACE-inhibitory activities of probiotic yogurt containing non-viable bacteria as affected by different levels of fat, inulin and starter culture

In this study, the effects of fat (0.5 %, 3.2 % and 5.0 %), inulin (0.0 and 1.0 %) and starter culture (0.0 %, 0.5 %, 1.0 % and 1.5 %) on the angiotensin converting enzyme (ACE)-inhibitory activity of probiotic yogurt containing non-viable bacteria were assessed. Proteolytic activities of bacteria were also investigated. Yogurts were prepared either using a sole yogurt commercial culture including Streptococcus thermophilus and Lactobacillus delbrueckii subs. bulgaricus or bifidobacterium animalis BB-12 and Lactobacillus acidophilus La5 in addition to yogurt culture. Relative degrees of proteolysis were found to be considerably higher in yogurt samples than UHT milk as the control. Both regular and probiotic yogurts showed considerable ACE-inhibitory activities. Results showed that degree of proteolysis was not influenced by different fat contents, while was increased by high concentration of starter culture (1.5 % w/w) and reduced by inulin (1 % w/w). ACE-inhibitory activities of yogurt were also negatively affected by the presence of inulin and high levels of fat (5 % w/w). Moreover, yogurt containing probiotic bacteria showed higher inhibitory against ACE in comparison to the yogurt prepared with non-probiotic strains.