Effects of added Lactobacillus acidophilus and Bifidobacterium lactis probiotics on the quality characteristics of goat ricotta and their survival under simulated gastrointestinal conditions

Short-communication: Study of fatty acid metabolites in microbial conjugated fatty acids-enrichment of milk and discovery of additional undescribed conjugated linolenic acid isomers

Microbially enriched food in conjugated linoleic (CLA) and conjugated linolenic (CLNA) acids is intensively studied nowadays. The conversion of linoleic (LA) and α-linolenic acids (α-LNA) into these compounds may involve different fatty acid (FA) intermediates. This research aimed to investigate potential FA byproducts in milk during microbial CLA/CLNA-enrichment using Bifidobacterium breve DSM 20091. Milk fermented with pure α-LNA showed a decrease in free myristic acid, while pure LA led to an increase in free stearic acid. No additional FA compounds were found alongside CLA/CLNA isomers. The strain produced several CLA isomers from LA, but only when administered alone. Nonetheless, when α-LNA was assayed, additional CLNA isomers, never reported before for bifidobacteria, were observed. In conclusion, except for stearic acid in the presence of LA, no side-FA metabolites were released during milk microbial CLA/CLNA-enrichment. Results suggest either CLA/CLNA production occurs in one single-step or intermediates biotransformation is very fast.

Proteolysis and therapeutic potential of bioactive peptides derived from Cheddar cheese

Cheddar cheese-derived bioactive peptides are considered a potential component of functional foods. A positive impact of bioactive peptides on diet-related chronic, non-communicable diseases, like obesity, cardiovascular diseases, and diabetes, has been observed. Bioactive peptides possess multifunctional therapeutic potentials, including antimicrobial, immunomodulatory, antioxidant, enzyme inhibitory effects, anti-thrombotic, and phyto-pathological activities against various toxic compounds. Peptides can regulate human immune, gastrointestinal, hormonal, and neurological responses, which play an integral role in the deterrence and treatment of certain diseases like cancer, osteoporosis, hypertension, and other health disorders, as described in the present review. This review summarizes the categories of the Cheddar cheese-derived bioactive peptides, their general characteristics, physiological functions, and possible applications in healthcare.

Probiotics: mechanism of action, health benefits and their application in food industries

Probiotics, like lactic acid bacteria, are non-pathogenic microbes that exert health benefits to the host when administered in adequate quantity. Currently, research is being conducted on the molecular events and applications of probiotics. The suggested mechanisms by which probiotics exert their action include; competitive exclusion of pathogens for adhesion sites, improvement of the intestinal mucosal barrier, gut immunomodulation, and neurotransmitter synthesis. This review emphasizes the recent advances in the health benefits of probiotics and the emerging applications of probiotics in the food industry. Due to their capability to modulate gut microbiota and attenuate the immune system, probiotics could be used as an adjuvant in hypertension, hypercholesterolemia, cancer, and gastrointestinal diseases. Considering the functional properties, probiotics are being used in the dairy, beverage, and baking industries. After developing the latest techniques by researchers, probiotics can now survive within harsh processing conditions and withstand GI stresses quite effectively. Thus, the potential of probiotics can efficiently be utilized on a commercial scale in food processing industries.

Evaluation of Pediococcus acidilacticiAS185 as an adjunct culture in probiotic cheddar cheese manufacture

A novel probiotic Pediococcus acidilactici AS185, isolated from traditional Chinese fermented foods, was used as an adjunct culture for probiotic cheddar cheese production. The physicochemical composition, textural, free amino acids (FAAs), short-chain fatty acids (SCFAs) profiles, sensory properties, and microbial survival, was evaluated during the 90-day ripening period. The addition of P. acidilactici AS185 did not influence the physicochemical composition of cheddar cheese but significantly decreased the hardness without affecting its textural profile. During ripening, P. acidilactici AS185 was able to grow and promote the generation of FAAs and SCFAs, but did not alter the overall sensory properties; it rather improved the flavor and taste of cheese. In addition, the cheese matrix protected strain P. acidilactici AS185 during transit throughout the simulated gastrointestinal system. These results demonstrated that P. acidilactici AS185 adjunct cultures might be useful for producing high-quality probiotic cheddar cheese.

Exploring the Potential of Sustainable Acid Whey Cheese Supplemented with Apple Pomace and GABA-Producing Indigenous Lactococcus lactis Strain

This study aimed to utilize two by-products, acid whey and apple pomace, as well as an indigenous Lactococcus lactis LL16 strain with the probiotic potential to produce a sustainable cheese with functional properties. Acid whey protein cheese was made by thermocoagulation of fresh acid whey and enhancing the final product by adding apple pomace, L. lactis LL16 strain, or a mixture of both. The sensory, the physicochemical, the proteolytic, and the microbiological parameters were evaluated during 14 days of refrigerated storage. The supplementation of the cheese with apple pomace affected (p ≤ 0.05) the cheese composition (moisture, protein, fat, carbohydrate, and fiber), the texture, the color (lightness, redness, and yellowness), and the overall sensory acceptability. The addition of the presumptive probiotic L. lactis LL16 strain decreased (p ≤ 0.05) the concentration of glutamic acid, thus increasing γ-aminobutyric acid (GABA) significantly in the acid whey cheese. The supplementation with apple pomace resulted in slightly (p < 0.05) higher counts of L. lactis LL16 on day seven, suggesting a positive effect of apple pomace components on strain survival. The symbiotic effect of apple pomace and LL16 was noted on proteolysis (pH 4.6-soluble nitrogen and free amino acids) in the cheese on day one, which may have positively influenced the overall sensory acceptance.

Probiotic fermented whey-milk beverages: Effect of different probiotic strains on the physicochemical characteristics, biological activity, and bioactive peptides

The effect of probiotic strains (Lactobacillus acidophilus La-03 (La-03); Lactobacillus acidophilus La-05 (La-05); Bifidobacterium Bb-12 (Bb-12) or Lacticaseibacillus casei-01 (L. casei-01)) on the characteristics of fermented whey-milk beverages during storage (4 °C, 30 days) was evaluated. The products were assessed for biological and antioxidant activities, physicochemical characteristics, and bioactive peptides. Probiotic addition increased α-amylase and α-glucosidase inhibition and antioxidant activities, mainly at 15 days of storage. L. casei-01 showed higher metabolic activity (higher titratable acidity and lower pH values) and the presence of anti-hypertensive peptides, while La-5 and Bb-12 showed higher α-glucosidase inhibition, improvements in the high saturated hypercholesterolemic index, and peptides with ACE-inhibitory, antimicrobial, immunomodulatory, and antioxidant activities. Our findings suggest that probiotic fermented whey-milk beverages may exert antidiabetic and antioxidant properties, being suggested La-5 or Bb-12 as probiotics and 15 days of storage.

Storage stability of texture, organoleptic, and biological properties of goat milk yogurt fermented with probiotic bacteria

Introduction

Goat milk is an attractive food due to its high nutritional values, easy digestibility and hypoallergenicity, but has an undesirable "goaty" flavor.

Methods

In this study, goat yogurt was fermented with four probiotics, respectively, including Lactobacillus acidophilus (GYA), Bifidobacterium animalis (GYB), Lactobacillus casei (GYC) and Lactobacillus plantarum (GYP), and tested for texture, organoleptic, and biological properties during a 4-week storage period at the refrigerated temperature.

Results

All goat yogurt with probiotics showed an increase on titratable acidity and a corresponding downward trend on pH value. Viable counts of L. acidophilus and L. casei were above 6 log cfu/mL at the end of the storage, which met the minimum standards for viable probiotic bacteria in yogurt specified by the Food and Agriculture Organization of United Nation (FAO). The texture and organoleptic characteristics of fermented goat milk depended on the strain and the storage period. DPPH free radical scavenging rate and ferric reducing antioxidant power activity gradually increased in all goat yogurts during the storage and yogurt with probiotic bacteria showed higher values than those of GY0.

Discussion

Among all probiotic containing goat yogurts, GYC exhibited the desirable characteristics of hardness, adhesiveness, water holding capacity, antioxidant activity during the whole storage. Furthermore, the addition of L. casei effectively weakened the goaty flavor and enhanced the overall acceptability. Thus, fermented goat milk with L. casei is optional for the development of goat milk product with satisfactory texture properties, pleasant sensory quality and high bioactivity.

Natural sources and encapsulating materials for probiotics delivery systems: Recent applications and challenges in functional food development

Probiotics are known as the live microorganisms which upon adequate administration elicit a health beneficial response inside the host by decreasing the luminal pH, eliminating the pathogenic bacteria in the gut as well as producing short chain fatty acids (SCFA). With advancements in research; probiotics have been explored as potential ingredients in foods. However, their use and applications in food industry have been limited due to restrictions of maintaining the viability of probiotic cells and targeting the successful delivery to gut. Encapsulation techniques have significant influence on increasing the viability rates of probiotic cells with the successful delivery of cells to the target site. Moreover, encapsulating techniques also prevent the live cells from harsh physiological conditions of gut. This review discusses several encapsulating techniques as well as materials derived from natural sources and nutraceutical compounds. In addition to this, this paper also comprehensively discusses the factors affecting the probiotics viability and evaluation of successful release and survival of probiotics under simulated gastric, intestinal conditions as well as bile, acid tolerant conditions. Lastly applications and challenges of using encapsulated bacteria in food industry for the development of novel functional foods have also been discussed in detail too. Future studies must include investigating the use of encapsulated bacterial formulations in in-vivo models for effective health beneficial properties as well as exploring the mechanisms behind the successful release of these formulations in gut, hence helping us to understand the encapsulation of probiotic cells in a meticulous manner.

Characterization of carotenoids double-encapsulated and incorporate in functional stirred yogurt

Carrot industry processing outputs 50% waste from raw materials; this waste contains polyphenols and carotenoids, which are a significant natural source of pro-vitamin A. Also, yogurt's high consumption globally allows for designing a new functional product. So the goal is to enhance the functionality of fortified stirred yogurt by incorporating carotenoid beads. The carotenoids were extracted from carrot waste using ultrasonication. Then nanoemulsion carotenoids incorporating with alginate to produce beads by extrusion technique. Measurement of carotenoid stability to nanoemulsion and beads. Manufactured five treatments of orange-flavored stirred yogurt and investigated its physicochemical properties, LAB survival, viscosity, and sensory acceptability. Findings – Carrot waste extract had about 44.75 ± 3.15 mg/g of β-carotene. The mean particle size of the nanoemulsion decreased with the increasing carotenoid addition (0.5%, 1%, and 1.5%) of carrot waste extract. The mean diameters of the alginate beads with nanoemulsions were 1.498 ± 0.245, 1.654 ± 0.310, and 1.792 ± 0.454 mm, respectively. The highest chemical stability of carotenoids showed with the alginate beads after Storage at 55°C to 14 days, compared with free or nanoemulsion carotenoids. Yogurt's physicochemical properties, viscosity, and LAB count improve when double-encapsulated carotenoids are added. Carotenoid double-encapsulation appeared to have a high ability to protect carotenoids from degradation and the ability to be applied in dairy and pharmaceutical products. Also, the resultant stirred yogurt with carotenoids-loaded beads gave carotenoids high stability and sensory acceptability.

Encapsulated Bifidobacterium BB-12 addition in a concentrated lactose-free yogurt: Its survival during storage and effects on the product's properties

This work aims to manufacture a new concentrated lactose-free probiotic yogurt. For this purpose, the probiotic Bifidocaterium BB-12 was incorporated in a concentrated lactose-free yogurt, both in its free form and previously encapsulated. Previous cell encapsulation was performed using the spray-drying technique with the following wall materials: lactose-free milk, lactose-free milk and inulin, and lactose-free milk and oligofructose. Thus, three different probiotic powders were obtained and added separately to three fractions of concentrated lactose-free yogurt. The probiotic survival of both powders and yogurts was evaluated during refrigerated storage. Likewise, the viability of starter cultures in yogurt (Lactobacillus bulgaricus and Streptococcus thermophilus) was controlled. In addition, the physicochemical properties of the four yogurts were also measured (color, pH and acidity, and texture properties). All three powders showed good probiotic viability (>8 log CFU g^-1) throughout 120 days of storage at 4 °C. In turn, yogurt formulations (with the addition of powders or free bifidobacteria) presented probiotic viability above 7 log CFU g^-1 after storage; as well as the starter cultures (>8 log UFC g^-1). Yogurt with probiotic powder from lactose-free milk showed a more yellowish color; however, these differences would not be detected by the human eye (ΔE < 3.00). The yogurt with bifidobacteria free cells showed a greater post-acidification process (pH 4.18 to 4.02 and titratable acidity 1.52 to 1.89). It was not observed differences for firmness values of yogurt with free cells addition and yogurt with lactose-free milk and oligofructose powder addition. A slight significant decrease in the cohesiveness was observed in the yogurt elaborated with bifidobacteria free cells. The gumminess showed fluctuating values between all concentrated lactose-free yogurts. At the end of this study, we conclude that these probiotic powders can be incorporated into innovative lactose-free yogurts.

Case Study on the Microbiological Quality, Chemical and Sensorial Profiles of Different Dairy Creams and Ricotta Cheese during Shelf-Life

This work investigated the microbiological quality and chemical profiles of two different dairy creams obtained by centrifugation vs. natural creaming separation systems. To this aim, an untargeted metabolomics approach based on UHPLC-QTOF mass spectrometry was used in combination with multivariate statistical tools to find potential marker compounds of the two different types of two dairy creams. Thereafter, we evaluated the chemical, microbiological and sensorial changes of a ricotta cheese made with a 30% milk cream (i.e., made by combining dairy creams from centrifugation and natural creaming separation) during its shelf-life period (12 days). Overall, microbiological analysis revealed no significant differences between the two types of dairy creams. On the contrary, the trend observed in the growth of degradative bacteria in ricotta during shelf-life was significant. Metabolomics revealed that triacylglycerols and phospholipids showed significant strong down-accumulation trends when comparing samples from the centrifugation and natural creaming separation methods. Additionally, 2,3-Pentanedione was among the best discriminant compounds characterising the shelf-life period of ricotta cheese (VIP score = 1.02), mainly related to sensorial descriptors, such as buttery and cheesy. Multivariate statistics showed a clear impact of the shelf-life period on the ricotta cheese, revealing 139 potential marker compounds (mainly included in amino acids and lipids). Therefore, the approach used showed the potential of a combined metabolomic, microbiological and sensory approach to discriminate ricotta cheese during the shelf-life period.

Probiotic infant cereal improves children's gut microbiota: Insights using the Simulator of Human Intestinal Microbial Ecosystem (SHIME®)

Infant́s gut microbiota can be modulated by many factors, including mode of delivery, feeding regime, maternal diet/weight and probiotic and prebiotic consumption. The gut microbiota in dysbiosis has been associated with innumerous diseases. In this sense, early childhood intestinal microbiome modulation can be a strategy for disease prevention. This study had the purpose to evaluate the effect of an infant cereal with probiotic (Bifidobacterium animalis ssp. lactis BB-12®) on infant́s intestinal microbiota using SHIME®, which simulates human gastrointestinal conditions. The ascending colon was inoculated with fecal microbiota from three children (2-3 years old). NH₄⁺, short chain fatty acids (SCFASs) and microbiota composition were determined by selective ion electrode, GC/MS and 16S sequencing, respectively. After treatment, butyric acid production increased (p < 0.05) 52% and a decrease in NH₄⁺ production was observed (p < 0.01). The treatment stimulated an increase (p < 0.01) of Lactobacillaceae families, more precisely L. gasseri and L. kefiri. L. gasseri has been associated with the prevention of allergic rhinitis in children and L. kefiri in the prevention of obesity. Thus, infant cereal with BB-12® is able to stimulate the growth of L. gasseri and L. kefiri in a beneficial way, reducing NH₄⁺ and increasing the production of SCFAs, especially butyric acid, in SHIME®.

Development of a semi-dynamic in vitro model and its testing using probiotic Bacillus coagulans GBI-30, 6086 in orange juice and yogurt

A dynamic system mimicking the gastrointestinal tract (GIT) conditions (fluids, pH, temperature, and residence time) was used to evaluate the behavior of Bacillus coagulans GBI-30, 6086 (BC) incorporated in yogurt and orange juice. BC counts were monitored in samples collected before the in vitro digestion, after initial contact with gastric fluids (30 min), static (1 h 15 min) and dynamic (2 h) stages in the gastric compartment, static (3 h) and dynamic (4 h) stages in the duodenal compartment, static (5 h) and dynamic (6 h) stages in the jejunal compartment, and after digestion. BC presented high survival in juice and yogurt over the digestion stages. The number of decimal reductions (γ) of BC caused by exposure to simulated GIT conditions was ≥0.89 in orange juice and ≥1.17 in yogurt. No differences (p ≥ 0.05) were observed on the survival of BC among the samples collected over the digestion in juice or yogurt, or between these matrices. After the in vitro digestion, BC counts were ≥7 log CFU/mL or g. Results show the great survival of BC under GIT conditions and suggest both, juice and yogurt as appropriate carries for delivering this probiotic to the diet. The semi-dynamic in vitro system was easily built and to operate, comprising an intermediate approach to assess the resistance of probiotic or potentially probiotic strains under simulated gut conditions.

Spreadable goat Ricotta cheese added with Lactobacillus acidophilus La-05: Can microencapsulation improve the probiotic survival and the quality parameters?

The impact of the addition of L. acidophilus La-05 (free cells, microencapsulated with alginate [30 g/L] or microencapsulated with alginate coated with chitosan [5 g/L]) on the quality parameters of spreadable goat Ricotta cheese during storage (7 °C/7 days) was evaluated. The addition of probiotic culture resulted in products with lower hardness, gumminess, and springiness, as well as higher cohesiveness and adhesiveness. Furthermore, it increased the yield, and altered the color (higher L*, a* and b* values). The microencapsulation of the probiotic cultures resulted in higher probiotic survival (>6 log CFU/mL in product and simulated gastrointestinal conditions), and improved technological (no moisture loss, lower proteolysis and organic acid content), texture (lower gumminess and adhesiveness), and volatile (compounds with floral and fruity notes and lower "goat" aroma) properties. Chitosan coating did not improve the effects. In conclusion, microencapsulation improved the probiotic survival and the quality parameters of spreadable goat Ricotta cheese.

Comparative effects of probiotic and paraprobiotic addition on microbiological, biochemical and physical properties of yogurt

Paraprobiotics are inactivated probiotics that exert various health and technological benefits making them suitable for production of functional yogurt. In the present study, probiotic yogurt containing Lactobacillus acidophilus ATCC SD 5221 and Bifidobacterium lactis BB-12 and paraprobiotic yogurt containing inactivated form of the mentioned bacteria were produced and were compared regarding microbiological, biochemical, and physical properties during 28 days of storage at refrigerated temperature. Results revealed that the greatest mean pH drop rate, mean acidity increase rate, mean redox potential increase rate, final acidity and final redox potential were observed in yogurt containing inactivated L. acidophilus added before fermentation. The highest lactic acid after 28 days of storage was obtained in samples prepared by addition of paraprobiotic form of L. acidophilus after fermentation. Yogurt samples with B. lactis and L. acidophilus added after fermentation showed the highest and lowest acetic acid level, respectively after 28 days of storage. The samples containing L. acidophilus and B. lactis had the highest acetaldehyde on day 0 while on day 28, L. acidophilus had more impact on acetaldehyde generation in yogurts. Addition of paraprobiotics increased viability of starter cultures. In addition, incorporation of inactivated probiotic cells into yogurt resulted in lower syneresis and the higher WHC compared to probiotic yogurt samples. Regarding color parameters, it was observed that color parameters (a*, b* and L*) were not influenced by paraprobiotic in probiotic and paraprobiotic yogurts. Overall, it can be concluded that incorporation of paraprobiotics into yogurt involves less technological challenges and can be considered as a suitable appropriate alternative for probiotics in development of functional yogurt.

Probiotics and prebiotics in non-bovine milk

Probiotics are live microorganisms that, when administered in adequate numbers, confer health benefit/s on the host, while prebiotics are nondigestible food ingredients that are selectively stimulate the growth of beneficial microorganisms in the distal parts of the host digestive tract conferring health benefits. Dairy products manufactured mainly using bovine milk is the major vehicle in delivering probiotics to humans. At present, there is an increasing demand for non-bovine probiotic milk products. Both bovine and non-bovine dairy products contain several ingredients with prebiotic properties such as oligosaccharides that could positively interact with probiotics to alter their functional properties. Furthermore, these bovine and non-bovine products could be fortified with prebiotics from various sources such as inulin and oligofructose in order to provide additional health benefits. In addition, non-bovine milk products are good sources for isolating novel potential probiotics. Non-bovine milk such as goat, sheep, camel and donkey have been used in producing several probiotic products including set-yoghurt, drinking-yoghurt, stirred-yoghurt, ice cream and cheese. Prebiotic inclusions in non-bovine milk at present is mainly associated with goat and sheep milk products. In this context, this chapter focuses on the different types of non-bovine milk products containing probiotics and prebiotics, and product quality and microbiological characteristics with special reference to probiotic viability.

Survival and Goat Milk Acidifying Activity of Lactobacillus rhamnosus GG Encapsulated with Agave Fructans in a Buttermilk Protein Matrix

Lactobacillus rhamnosus GG (L. rhamnosus GG) cells were encapsulated in buttermilk proteins by spray drying, alone (E), or with Agave tequilana fructans (CEF). Buttermilk proteins acted as a thermo-protector for the probiotic cells undergoing the spray-dried process. The addition of Agave fructans in CEF microcapsules significantly enhanced storage stability and survival to in vitro simulated gastrointestinal conditions, compared to E capsules. After 14 days storage at - 20 °C, the number of living cells in CEF microcapsules was in the order of 7.7 log CFU • mL^-1 and the survivability in simulated gastrointestinal environment was 73.23%. Spray-dried microparticles were cultured in goat milk to study biomass production. Agave fructans offered a favorable microenvironment and better growth substrate. The population of CEF viable cells reached 1.08 ± 0.02 × 10¹⁰ CFU • mL^-1 after 18 h of fermentation. In contrast, the population of E viable cells were 3.0 ± 0.01 × 10⁹ CFU • mL^-1. The generation time of CEF, L. rhamnosus GG was 15% faster than E, L. rhamnosus GG. Encapsulation with buttermilk proteins in the presence of Agave fructans by spray drying could be suitable for preservation of probiotic powders and may be for a more effective application of probiotics in goat dairy products.

Cheese as a Potential Food Carrier to Deliver Probiotic Microorganisms into the Human Gut: A Review

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This review presents the industrial manufacture and applications of cheese for the delivery of probiotic microorganisms into the human gut. Initially, important benefits of probiotics and advantageous characteristics of cheese for the delivery of probiotic microorganisms into the human gut in comparison with the other fermented milk products are discussed. Fresh and ripened cheeses are also separately argued followed by discussing queries respecting the viability of probiotic bacteria into these cheeses. Since fresh cheese has been demonstrated as more suitable carriers for probiotic microorganisms, factories are recommended producing it in large quantities.

Recent advances in dairy goat products

Goat population world-wide is increasing, and the dairy goat sector is developing accordingly. Although the new technology applied to the goat industry is being introduced slowly because the weight of traditional subsector in the dairy sector, considerable advances have been made in the last decade. Present review focuses on the emerging topics in the dairy goat sector. Research and development of traditional and new dairy goat products are reviewed, including the new research in the use of goat milk in infant formula. The research in alternatives to brine, production of skimmed goat cheeses and the use of different modified atmosphere packaging are also addressed. Special attention is given to antibiotic residues and their determination in goat milk. Functional foods for human benefits are a trending topic. Health properties recently discovered in dairy goat products are included in the paper, with special attention to the antioxidant activity. The dual-purpose use of goats by humankind is affecting the way of how new technology is being incorporated in the dairy goat sector and will certainly affect the future development of dairy goat products.

Probiotics in Goat Milk Products: Delivery Capacity and Ability to Improve Sensory Attributes

Dairy foods, particularly those of bovine origin, are the predominant vehicles for delivery of probiotic bacteria. Caprine (goat) milk also possesses potential for successful delivery of probiotics, and despite its less appealing flavor in some products, the use of goat milk as a probiotic carrier has rapidly increased over the last decade. This review reports on the diversity, applicability, and potential of using probiotics to enhance the sensory properties of goat milk and goat milk-based products. A brief conceptual introduction to probiotic microorganisms is followed by an account of the unique physicochemical, nutritive, and beneficial aspects of goat milk, emphasizing its advantages as a probiotic carrier. The sensory properties of probiotic-enriched goat milk products are also discussed. The maintenance of probiotic viability and desirable physicochemical characteristics in goat milk products over shelf life is possible. However, the unpleasant sensory features of some goat milk products remain a major disadvantage that hinder its wider utilization. Nevertheless, certain measures such as fortification with selected probiotic strains, inclusion of fruit pulps and popular flavor compounds, and production of commonly consumed tailor-made goat milk-based products have potential to overcome this limitation. In particular, certain probiotic bacteria release volatile compounds as a result of their metabolism, which are known to play a major role in the aroma profile and sensory aspects of the final products.

Review: Adaptation of Beneficial Propionibacteria, Lactobacilli, and Bifidobacteria Improves Tolerance Toward Technological and Digestive Stresses

This review deals with beneficial bacteria, with a focus on lactobacilli, propionibacteria, and bifidobacteria. As being recognized as beneficial bacteria, they are consumed as probiotics in various food products. Some may also be used as starters in food fermentation. In either case, these bacteria may be exposed to various environmental stresses during industrial production steps, including drying and storage, and during the digestion process. In accordance with their adaptation to harsh environmental conditions, they possess adaptation mechanisms, which can be induced by pretreatments. Adaptive mechanisms include accumulation of compatible solutes and of energy storage compounds, which can be largely modulated by the culture conditions. They also include the regulation of energy production pathways, as well as the modulation of the cell envelop, i.e., membrane, cell wall, surface layers, and exopolysaccharides. They finally lead to the overexpression of molecular chaperones and of stress-responsive proteases. Triggering these adaptive mechanisms can improve the resistance of beneficial bacteria toward technological and digestive stresses. This opens new perspectives for the improvement of industrial processes efficiency with regard to the survival of beneficial bacteria. However, this bibliographical survey evidenced that adaptive responses are strain-dependent, so that growth and adaptation should be optimized case-by-case.

Technological Properties of Bifidobacterial Strains Shared by Mother and Child

Technological processes in the dairy industry and the further passage through the gastrointestinal tract could impair viability and functionality of probiotic bifidobacteria. In the present work, the growth in milk of nine bifidobacterial strains shared by mother and child, their survival to freeze-drying and cold storage, and their behavior in a model cheese were investigated. All the strains exhibited high stability to the technological conditions studied when compared with two commercial strains. Bifidobacterium breve INIA P734 and Bifidobacterium bifidum INIA P671 as adjunct cultures maintained high stability during manufacture and ripening of cheese. Both strains showed, at the end of ripening period, resistance to simulated gastrointestinal conditions. Moreover, their presence did not affect negatively the quality of cheese. B. breve INIA P734 and B. bifidum INIA P671 could be considered as potential candidates for their use in cheese as adjunct cultures.

In vitro gastrointestinal resistance of Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 in soy and/or milk-based synbiotic apple ice creams

The viability and resistance to simulated gastrointestinal (GI) conditions of Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 in synbiotic ice creams, in which milk was replaced by soy extract and/or whey protein isolate (WPI) with inulin, were investigated. The ice creams were showed to be satisfactory vehicles for La-5 and Bb-12 (populations around 7.5logCFU/g), even after the whole storage period (84days/-18°C). In all formulations, the propidium monoazide qPCR (PMA-qPCR) analysis demonstrated that probiotics could resist the in vitro GI assay, with significant survival levels, achieving survival rates exceeding 50%. Additionally, scanning electron microscopy images evidenced cells with morphological differences, suggesting physiological changes in response to the induced stress during the in vitro assay. Although all formulations provided resistance to the probiotic strains under GI stress, the variation found in probiotic survival suggests that GI tolerance is indeed affected by the choice of the food matrix.

Characteristics and Application in Food Preservatives of Lactobacillus plantarum TK9 Isolated from Naturally Fermented Congee

In the present research, a strain of Lactobacillus plantarum TK9 was isolated from the Chinese naturally fermented congee and its characteristics for probiotic and food preservation were investigated. In terms of probiotic, the strain not only survives bile salts and simulated gastric juice but grows well under hypertonic conditions. Besides, the L. plantarum TK9 exhibited a broad antifungal spectrum, including most of the species closely related to food spoilage, like Penicillium roqueforti, Penicillium citrinum, Penicillium oxalicum, Aspergillus fumigatus, Aspergillus flavus and Rhizopus nigricans. But no evident inhibition effect was found on Aspergillus niger. To further evaluate its potential as bio-preservative, L. plantarum TK9 was inoculated into citrus, apples and yogurt prior to the addition of moulds. The results indicated that L. plantarum TK9 could obviously prolong shelf life of the test food for 72–96 h and represent an excellent candidate for food-related bio-preservative.

Influence of the addition of Lactobacillus acidophilus La-05, Bifidobacterium animalis subsp. lactis Bb-12 and inulin on the technological, physicochemical, microbiological and sensory features of creamy goat cheese

We evaluated the effects of addition of probiotic cultures and inulin on the quality of creamy goat cheese.