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

Comprehensive analysis of phospholipid in milk and their biological roles as nutrients and biomarkers

Phospholipids (PL) have garnered significant attention due to their physiological activities. Milk and other dairy products are important dietary sources for humans and have been extensively used to analyze the presence of PL by various analytical techniques. In this paper, the analysis techniques of PL were reviewed with the eight trigrams of phospholipidomics and a comprehensive fingerprint of 1295 PLs covering 8 subclasses in milk and other dairy products, especially. Technology is the primary productive force. Based on phospholipidomics technology, we further review the relationship between the composition of PL and factors that may be involved in processing and experimental operation, and emphasized the significance of the biological role played by PL in dietary supplements and biomarkers (production, processing and clinical research), and providing the future research directions.

Potential role of camel, mare milk, and their products in inflammatory rheumatic diseases

Milk and dairy products serve as a significant dietary component for people all over the world. Milk is a source of essential nutrients such as carbohydrates, protein, fats, and water that support newborns' growth, development, and physiological processes. Milk contains various essential biological compounds that contribute to overall health and well-being. These compounds are crucial in immune system regulation, bone health, and gut microbiota. Milk and dairy products are primarily from cows, buffalos, goats, and sheep. Recently, there has been a notable increase in camel and mare milk consumption and its associated products due to an increasing attraction to ethnic cuisines and a greater awareness of food biodiversity. Camel and mare milk possess diverse nutritional and therapeutic properties, displaying potential functional foods. Camel milk has been linked to various health advantages, encompassing antihypertensive, antidiabetic, antiallergic, anticarcinogenic, antioxidant, and immunomodulatory properties. Camel milk has exhibited notable efficacy in mitigating inflammation and oxidative stress, potentially offering therapeutic benefits for inflammatory disorders. Nevertheless, although extensively recorded, the potential health benefits of mare's milk have yet to be investigated, including its impact on inflammatory conditions. This article highlights the therapeutic potential of camel and mare milk and its derived products in treating inflammatory rheumatic disorders, specifically focusing on their anti-inflammatory and immune-regulatory capabilities. These alternative types of milk, which do not come from cows, offer potential avenues for investigating innovative strategies to regulate and reduce inflammatory conditions.

Milk and Its Derivatives as Sources of Components and Microorganisms with Health-Promoting Properties: Probiotics and Bioactive Peptides

Milk is a source of many valuable nutrients, including minerals, vitamins and proteins, with an important role in adult health. Milk and dairy products naturally containing or with added probiotics have healthy functional food properties. Indeed, probiotic microorganisms, which beneficially affect the host by improving the intestinal microbial balance, are recognized to affect the immune response and other important biological functions. In addition to macronutrients and micronutrients, biologically active peptides (BPAs) have been identified within the amino acid sequences of native milk proteins; hydrolytic reactions, such as those catalyzed by digestive enzymes, result in their release. BPAs directly influence numerous biological pathways evoking behavioral, gastrointestinal, hormonal, immunological, neurological, and nutritional responses. The addition of BPAs to food products or application in drug development could improve consumer health and provide therapeutic strategies for the treatment or prevention of diseases. Herein, we review the scientific literature on probiotics, BPAs in milk and dairy products, with special attention to milk from minor species (buffalo, sheep, camel, yak, donkey, etc.); safety assessment will be also taken into consideration. Finally, recent advances in foodomics to unveil the probiotic role in human health and discover novel active peptide sequences will also be provided.

Safety assessment, whole genome sequence, and metabolome analysis of Streptococcus thermophilus CICC 20372 for bone cement fermentation

Bone is a kind of meat processing by-product with high nutritional value but low in calorie, which is a typical food in China and parts of East Asian countries. Microbial fermentation by lactic acid bacteria showed remarkable advantages to increase the absorption of nutrients from bone cement by human body. Streptococcus thermophilus CICC 20372 is proven to be a good starter for bone cement fermentation. No genes encoding virulence traits or virulence factors were found in the genome of S. thermophilus CICC 20372 by a thorough genomic analysis. Its notable absence of antibiotic resistance further solidifies the safety. Furthermore, the genomic analysis identified four types of gene clusters responsible for the synthesis of antimicrobial metabolites. A comparative metabolomic analysis was performed by cultivating the strain in bone cement at 37 °C for 72 h, with the culture in de Man, Rogosa, and Sharpe (MRS) medium as control. Metabolome analysis results highlighted the upregulation of pathways involved in 2-oxocarboxylic acid metabolism, ATP-binding cassette (ABC) transporters, amino acid synthesis, and nucleotide metabolism during bone cement fermentation. S. thermophilus CICC 20372 produces several metabolites with health-promoting function during bone cement fermentation, including indole-3-lactic acid, which is demonstrated ameliorative effects on intestinal inflammation, tumor growth, and gut dysbiosis. In addition, lots of nucleotide and organic acids were accumulated at higher levels, which enriched the fermented bone cement with a variety of nutrients. Collectively, these features endow S. thermophilus CICC 20372 a great potential strain for bone food processing.

Analysis for different flavor compounds in mature milk from human and livestock animals by GC × GC-TOFMS

Breast milk plays a crucial role in the taste development of infants, which cannot be replicated by other mammalian milk or formulas. This study aimed to identify and characterize the flavor substances in 15 different types of milk and analyze the differences among them. The results showed that human milk contained high levels of esters, particularly fatty acid ethyl esters, which contribute to its unique flavor. The four substances that had the highest flavor contribution in all species were identified as 2,3-butanedione, trimethylamine, isophorone, and acetaldehyde. Furthermore, the analysis of differences revealed that thermal-oxidation of lipids could explain the variation between human milk and other species in terms of flavor compounds. The key differential flavor compounds identified in milk from all species were trimethylamine, propanal, 1-pentanol, pyridine 2-methyl, and 2-butanone. These findings can potentially aid in developing formulas that better meet the taste needs of infants.

The Impact of Pulsed Electric Fields on Milk's Macro- and Micronutrient Profile: A Comprehensive Review

Consumers around the world are attracted to products with beneficial effects on health. The stability, functionality, and integrity of milk constituents are crucial determinants of product quality in the dairy industry. Milk contains macronutrients and micronutrients that aid in a wide range of physiological functions in the human body. Deficiencies of these two types of nutrients can confine growth in children and increase the risk of several diseases in adults. The influence of pulsed electric fields (PEF) on milk has been extensively reviewed, mostly concentrating on the inactivation of microbes and enzymes for preservation purposes. Therefore, the information on the variations of milk macro- and micronutrients treated by PEF has yet to be elucidated and it is imperative as it may affect the functionality, stability, and integrity of the milk and dairy products. In this review, we describe in detail the introduction, types, and components of PEF, the inactivation mechanism of biological cells by PEF, as well as the effects of PEF on macro- and micronutrients in milk. In addition, we also cover the limitations that hinder the commercialization and integration of PEF in the food industry and the future outlook for PEF. The present review consolidates the latest research findings investigating the impact of PEF on the nutritional composition of milk. The assimilation of this valuable information aims to empower both industry professionals and consumers, facilitating a thorough understanding and meticulous assessment of the prospective adoption of PEF as an alternative technique for milk pasteurization.

Artisanal Goat Coalho Cheese with Cachaça as Flavoring Agent

Cachaça is a traditional Brazilian drink that has the potential to offer a new sensory and technological strategy for artisanal cheesemaking, particularly for small-scale producers and family farming. This study aimed to investigate the effects of cachaça immersion on the physicochemical, microbiological, color, texture, and sensory parameters of artisanal goat coalho cheeses using three different varieties of cachaça immersion. The results showed that cachaça immersion did not affect the cheese's proximate composition or starter culture viability, indicating its suitability as a new method for artisanal cheese production. Additionally, gold cachaça aged in oak casks was the most effective variety for sensory acceptance and purchase intention, suggesting that it may be a valuable strategy for small-scale producers to add value and encourage the consumption of artisanal goat coalho cheeses without compromising their quality. Thus, this study provides important insights for small-scale producers and family farming to enhance their product offerings and increase their competitiveness in the market.

Screening and Identification of Goat-Milk-Derived Lactic Acid Bacteria with Bacteriocin-like Activity and Probiotic Potentials

In the current study, we screened 46 isolates of lactic acid bacteria (LAB) derived from goat milk for bacteriocin producers that can inhibit common foodborne pathogens (Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus). The following three strains that showed antimicrobial activity against all indicators were identified: Enterococcus faecalis DH9003 and DH9012, and Lactococcus lactis DH9011. Their antimicrobial products exhibited typical bacteriocin characteristics, such as heat stability and proteinase nature. The bacteriostatic activity of concentrated bacteriocins produced by these LAB was observed at low concentrations (half-minimum inhibitory concentration [MIC50] and 4MIC50), whereas complete inhibition activity against Listeria monocytogenes was detected at high concentrations (16MIC50) of the two Enterococcus faecalis strains (DH9003 and DH9012). Furthermore, the probiotic potentials of the three strains were investigated and described. The results revealed that none of the strains had hemolytic activity, whereas all: were sensitive to ampicillin (50 mg/mL) and streptomycin sulfate (100 mg/mL); were resistant to bile, artificial simulated intestinal tract, and gastric juice at different pH levels (2.5, 3.0, 3.5); and had β-galactosidase activity. Furthermore, all strains exhibited an auto-aggregating phenotype, with self-aggregation ranging from 30% to 55%. DH9003 and DH9012 co-aggregated well with Listeria monocytogenes and Escherichia coli (52.6% and 63.2%, 68.5% and 57.6%, respectively), whereas DH9011 co-aggregated poorly with Listeria monocytogenes (15.6%) and did not co-aggregate with Escherichia coli. Furthermore, our results showed that all three isolates exhibited strong antibacterial activity, tolerance to bile and simulated gastrointestinal environments, adhesion capability, and safety. Finally, DH9003 was selected and used for gavage in rats. By observing the pathological characteristics of rat intestinal and liver tissue sections, DH9003 showed no harmful effects on the intestine and liver of rats, but rather resulted in a denser and longer intestinal mucosa, as well as improving the intestinal mucosa of rats. Considering their substantial prospective applications, we concluded that these three isolates are potential probiotic candidates.

Effect of Storage Time and Bacterial Strain on the Quality of Probiotic Goat's Milk Using Different Types and Doses of Collagens

Recently, increasing attention has been focused on developing new products based on goat’s milk. Consumers positively perceive fermented goat’s milk products as health-promoting due to their nutritional value, digestibility, and potential source of probiotics. This study aimed to evaluate the possibility of using different doses of collagen and collagen hydrolysate in the production of probiotic goat’s milk fermented by four monocultures: Lacticaseibacillus casei 431® Lactobacillus acidophilus LA- 5®, Lacticaseibacillus paracasei LP26, and Lacticaseibicillus rhamnosus Lr- 32®. A total of 20 experimental groups were prepared, including control groups (without additives), and due to the added probiotic (Lacticaseibacillus casei, Lactobacillus acidophilus, Lacticaseibacillus paracasei, and Lacticaseibacillus rhamnosus), various collagen doses (1.5% and 3.0%) and collagen types (hydrolysate and bovine collagen). Physicochemical, organoleptic, and microbiological characteristics were evaluated after 1 and 21 days of cold storage. The applied additives increased the acidity of the milk even before fermentation. However, milk with bovine collagen and hydrolysate had a higher pH value after fermentation than control milk. The study showed higher than 8 log cfu g−1 viability of probiotic bacteria in goat’s milk products during storage due to the proper pH, high buffering capacity, and rich nutrient content of goat’s milk. The best survival rate was shown for the L. casei strain after 21 days in milk with collagen protein hydrolysate. Moreover, collagen in milk fermented by L. rhamnosus decreased syneresis compared to its control counterpart. The addition of collagen, especially the hydrolysate, increased the gel hardness of the fermented milk. The collagen additives used in the milk, both in the form of hydrolysate and bovine collagen, caused a darkening of the color of the milk and increased the intensity of the milky-creamy and sweet taste.

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.

Antagonist action of Lactobacillus acidophilus against pathogenic strains in goat milk yogurt

Contamination by pathogenic bacteria is the major cause of foodborne diseases, which is an international public health issue. Probiotics added to fermented milk can fight against these pathogens. This research aimed to evaluate, by mathematical models, the behaviour of Lactobacillus acidophilus against pathogenic strains inoculated in goat milk yogurt. The Baranyi and Roberts' model was adjusted to data and statistically evaluated. A greater pathogens reduction occurred in the samples supplemented with probiotics, which exhibited antimicrobial activity against Pseudomonas aeruginosa. The reduction was less efficient against Escherichia coli. The primary models adjustment indicated that the Baranyi and Roberts fitted the reduction of P. aeruginosa, Salmonella typhimurium, E. coli and Staphylococcus aureus inactivation. The addition of L. acidophilus proved to be an effective alternative for the safer production of goat milk yogurt.

Spray Drying Encapsulation of Pediococcus acidilactici at Different Inlet Air Temperatures and Wall Material Ratios

Pediococcus acidilactici has gained research and commercial interest due to its outstanding probiotic properties, yet its survival during storage and consumption requires improvement. This study aims to enhance P. acidilactici survival using spray drying encapsulation. Different inlet air temperatures (120 °C, 150 °C, and 170 °C) and whey protein isolate (WPI):gum arabic (GA) ratios (1:1, 3:1, 1:3) were tested. Cell viability was significantly (p < 0.05) affected by the inlet temperature but not the WPI:GA ratio. Increasing the inlet temperature to 170 °C significantly decreased P. acidilactici viability by 1.36 log cycles, from 8.61 log CFU/g to 7.25 log CFU/g. The inlet temperature of 150 °C resulted in a powder yield (63.12%) higher than at 120 °C (58.97%), as well as significantly (p < 0.05) lower moisture content (5.71%) and water activity (aw 0.21). Viable cell counts in all encapsulated P. acidilactici were maintained at 5.24−6.75 log CFU/g after gastrointestinal tract (GIT) simulation, with WPI:GA of 3:1 and inlet temperature 150 °C having the smallest log reduction (0.3 log cycles). All samples containing different WPI:GA ratios maintained sufficient viability (>7 log CFU/g) during the first three weeks of storage at 25 °C. These results could provide insights for further developing P. acidilactici as commercial probiotic products.

Advances in characterization of probiotics and challenges in industrial application

An unbalanced diet and poor lifestyle are common reasons for numerous health complications in humans. Probiotics are known to provide substantial benefits to human health by producing several bioactive compounds, vitamins, short-chain fatty acids and short peptides. Diets that contain probiotics are limited to curd, yoghurt, kefir, kimchi, etc. However, exploring the identification of more potential probiotics and enhancing their commercial application to improve the nutritional quality would be a significant step to utilizing the maximum benefits. The complex evolution patterns among the probiotics are the hurdles in their characterization and adequate application in the industries and dairy products. This article has mainly discussed the molecular methods of characterization that are based on the analysis of ribosomal RNA, whole genome, and protein markers and profiles. It also has critically emphasized the emerging challenges in industrial applications of probiotics.

Development and characterization of lactose-free probiotic goat milk beverage with bioactive rich jambo pulp

Goat milk is considered a suitable matrix for the successful incorporation of probiotics, also obtaining new lactose-free fermented products can expand its use. This study aimed to develop and characterize formulations of lactose-free probiotic fermented goat dairy beverages as well as to determine the most appropriate concentration of red jambo pulp to be added. The beverages were developed with different concentrations of lactose-free goat milk and frozen jambo pulp (12, 15 and 18% w/v) and lyophilized (3, 6 and 9% w/v), corresponding to formulations F1 to F6, respectively, as source of bioactive compounds. Probiotics counts decreased significantly (from 8.58 to 7.38 log CFU mL-1). The formulation with a higher proportion of lyophilized (F6) pulp showed the highest levels of phenolic compounds (72.08 mg GAE 100 g-1), anthocyanins (50.80 mg cyanidin-3-glycoside 100 g-1), ascorbic acid (41.68 mg 100 g-1), and antioxidant activity (16.21 μmol TE g-1) (P < 0.05). On the other hand, F3 presented the highest global acceptance and purchase intention (P < 0.05). However, the principal component analysis (PCA) indicated that the components related to bioactive compounds (PC1) stood out on sensory attributes (PC3 and PC4) and, therefore, F6 was most appropriate for obtaining a lactose-free goat probiotic fermented milk with improved bioactive properties targeting lactose intolerant consumers and those who are allergic to bovine milk proteins.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05399-z.

Characterization of autochthonous lactobacilli from goat dairy products with probiotic potential for metabolic diseases

The present study aimed to design functional fermented goat milk with probiotic potential for metabolic diseases. Thereby, autochthonous lactobacilli from goat dairy products that target improving the inflammatory, lipid, and glycemic profile were characterized. We designed fermented goat milk using Lactobacillus delbrueckii subsp. indicus CRL1447 as starter strain, supplemented with different probiotic consortia formed by Limosilactobacillus fermentum CRL1446, Lactiplantibacillus paraplantarum CRL1449, and CRL1472 strains. These lactobacilli were selected for their positive effects on inhibition of α-glucosidase, bile salts hydrolase activity, cholesterol assimilation, and decreased triglyceride percentage in Caenorhabditis elegans. Furthermore, the lactobacilli oral administration to obese mice caused a significant decrease in body weight gain and ameliorated hyperglycemia and hyperlipemia. These results reveal the potential of this goat dairy product as a functional food to prevent obesity and related pathologies. Goat milk-derived products stand out for their marketing potential. Hence, fermented goat milk incorporating novel probiotics represents a group of food products with broad prospects by their promising nutritive and therapeutic properties for metabolic diseases. The goat dairy product designed in this study could be used in the prevention of dyslipidemia and hyperglycemia in obese people.

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New probiotic consortium (CRL1449, CRL1472, and ​CRL1446) was selected.

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The probiotic consortium showed in vitro immuno and adipomodulatory properties.

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Lactobacillus delbrueckii subsp. indicus CRL1447 was selected as a starter culture for fermented milk elaboration.

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Manufacturing of a functional fermented goat milk with a new probiotic consortium.

An insight into the health beneficial of probiotics dairy products: a critical review

Probiotic dairy products satisfy people's pursuit of health, and are widely favored because of their easy absorption, high nutritional value, and various health benefits. However, its effectiveness and safety are still controversial. This proposal aims to analyze the effect of probiotics on the quality characteristics of dairy products, clarify a series of physiological functions of probiotic dairy products and critically evaluate the effectiveness and safety of probiotic dairy products. Also, dairy products containing inactivated microorganisms were compared with probiotic products. The addition of probiotics enables dairy products to obtain unique quality characteristics, and probiotic dairy products have better health-promoting effects. This review will promote the further development of probiotic dairy products, provide directions for the research and development of probiotic-related products, and help guide the general public to choose and purchase probiotic fermentation products.

The Improvement of Sensory and Bioactive Properties of Yogurt with the Introduction of Tartary Buckwheat

The incorporation of cereals in yogurt has recently gained increasing consumer approval, for its high nutritional value and health benefits, all over the world. Following this emerging trend, Tartary buckwheat (TB) was supplemented into yogurt as a natural functional ingredient in order to develop a yogurt with enhanced product characteristics and consumer acceptability. The impact of TB addition on physicochemical properties (pH, acidity, apparent viscosity, etc.) and the viability of lactic acid bacteria in yogurt was investigated. It is found that the TB introduction can reduce the pH, increase the acidity and apparent viscosity, and also greatly boost the bioactivities of yogurt. Response surface analysis demonstrated that yogurt with 8 g of TB, 10 g of sugar, and a fermentation duration of 5 h had the highest overall acceptability, and these cultural conditions were chosen as the best. Furthermore, the TB-added yogurt had not only a better sensory and aroma profile, but also good prospective health advantages when compared to regular yogurt. Our research shows that adding TB to yogurt has a significant positive impact on both overall quality and sensory characteristics, making a compelling case for using TB yogurt and developing new fermented dairy products.

DNA-based qualitative and quantitative identification of bovine whey powder in goat dairy products

As one of the main ingredients in some milk powders, whey powder is sometimes added to pure goat milk products, which causes health risks, economic fraud, and unfair competition of food industries. This study is the first to explore qualitative and quantitative methods to identify adulteration of bovine whey powder in goat dairy products based on DNA. We extracted DNA from whey powder using a modified DNA extraction method; this exhibited good quality and integrity, with purity of 1.53 to 1.75 and concentration of 122 to 179 ng/μL. Conventional PCR and real-time PCR were compared for qualitative detection of bovine whey powder; real-time PCR demonstrated sensitivity of 0.01 ng/μL, which was higher than the 0.05 ng/μL detected by the conventional PCR method. Furthermore, real-time PCR was conducted for DNA quantitative detection, with good linearity (R² = 0.9858) obtained for bovine whey powder contents from 0.1% to 30%. Relative error decreased with increase of the mixing proportion of whey powder; the coefficient of variation above 0.1% of the mixing ratio was close to or less than 5%; and the relative standard deviation of repeatability results was less than 5%. Considering the economic costs of testing, conventional PCR could be performed first, and samples with obvious intentional adulteration detected can be further accurately quantified by real-time PCR. Overall, this research provides a realistic and effective method for qualitative and quantitative identification of bovine whey powder in goat dairy products, thus laying a good foundation for verification of goat dairy product label claims and industrial control.

The Use of Olkuska Sheep Milk for the Production of Symbiotic Dairy Ice Cream

Simple Summary

Ice cream may be used as a carrier to deliver probiotics and prebiotics. In this study, we decided to investigate the possibility of using sheep milk from the Olkuska breed for ice cream manufacture and evaluate the viability of Lactobacillus and Lacticaseibacillus strains and the chemical, physical and organoleptic properties of dairy ice cream during storage. The obtained results contribute to a more practical application of different probiotic strains for the fermentation of ice cream mixes and the possibility of using apple fiber in ice cream production. Moreover, the study’s findings showed that symbiotic ice cream with acceptable physicochemical and organoleptic characteristics might be produced from sheep milk of the Olkuska breed.

Abstract

The aim of this study was to determine the possibility of using Olkuska sheep milk for the production of ice cream with probiotics and prebiotics. The study examined the effect of the storage and type of bacteria used for the fermentation of ice cream mixes and partial replacement of inulin with apple fiber on the physicochemical properties, viability of probiotic cultures and organoleptic properties of sheep’s milk ice cream stored at −22 °C for 21 days. The addition of apple fiber reduced the pH value of ice cream mixes before fermentation. In ice cream mixes and ice cream with apple fiber, the lactic acid content was higher by 0.1–0.2 g L⁻¹ than in their equivalents with inulin only. These differences persisted during the storage of the ice cream. After fermentation of the ice mixes, the bacterial cell count ranged from 10.62 log cfu g⁻¹ to 12.25 log cfu g⁻¹. The freezing process reduced the population of probiotic bacteria cells in ice cream with inulin from 0.8 log cfu g⁻¹ in ice cream with Lactobacillus acidophilus, 1.0 log cfu g⁻¹ in ice cream with Lacticaseibacillus paracasei and 1.1 log cfu g⁻¹ in ice cream with Lacticaseibacilluscasei. Freezing the varieties with apple fiber also resulted in a reduction of viable bacterial cells from 0.8 log cfu g⁻¹ in ice cream with L. paracasei and Lb. acidophilus to 1 log cfu g⁻¹ in ice cream with L. casei, compared to the results after fermentation. The highest percentage overrun was determined in ice cream with L. paracasei and Lb. acidophilus. Ice cream with L. casei was characterized by significantly lower overrun on the 7th and 21st days of storage. Although L. paracasei ice cream had the highest overrun, it did not cause a significant reduction in the probiotic population during storage. After seven days of storage, the first drop differed significantly depending on the type of bacteria used for fermentation of the mixture and the addition of apple fiber. L. casei ice cream had a longer first drop time than L. paracasei and Lb. acidophilus ice cream. Partial replacement of inulin with apple fiber resulted in a significant darkening of the color of ice cream mixes. Depending on the type of bacteria used for fermentation, the addition of apple fiber decreased the value of the L* parameter. Ice cream mixes and ice cream with inulin and apple fiber were characterized by a high proportion of yellow. Partial replacement of inulin with apple fiber reduced the hardness of ice cream compared to inulin-only ice cream. Moreover, the panelists found that ice cream with inulin was characterized by a sweeter taste than ice cream with apple fiber. Moreover, the addition of apple fiber favorably increased the flavor and aroma perception of the mango-passion fruit. Therefore, the milk of Olkuska sheep could be successfully used for the production of symbiotic dairy ice cream.

Recent Insights Into Processing Approaches and Potential Health Benefits of Goat Milk and Its Products: A Review

Goat milk is considered to be a potential source of various macro- and micro-nutrients. It contains a good proportion of protein, fat, carbohydrates, and other nutritional components which help in promoting nutritional and desirable health benefits. Goat milk is considered to be superior in terms of numerous health benefits, and lower risk of allergy, when compared to the milk of other species. Several processing techniques such as pasteurization, ultrafiltration, microfiltration, and ultrasound have been employed to enhance the quality and shelf life of goat milk and its products. The diverse range of goat milk-based products such as yogurt, cheese, fermented milk, goat milk powder, and others are available in the market and are prepared by the intervention of advanced processing technologies. Goats raised in pasture-based feeding systems are shown to have a better milk nutritional composition than its counterpart. Goat milk contains potential bioactive components, which aids in the maintenance of the proper metabolism and functioning of the human body. This review gives insight into the key nutritional ingredients and bioactive constituents present in goat milk and their potential role in the development of various functional foods using different processing technologies. Goat milk could be considered as a significant option for milk consumption in infants, as compared to other milk available.

Rheological and textural properties of goat's milk set-type yoghurt as affected by heat treatment, transglutaminase addition and storage

BACKGROUND

Production of goat's milk set-style yoghurt encounters challenges in achieving the texture characteristic for this type of product, primarily due to protein composition of this milk. This study evaluated the effects of using microbial transglutaminase (mTGase) concomitantly with starter culture in the production of goat's milk yoghurt - a method that has not been employed with this milk type until now- indicating the potential of the enzyme to change yoghurt's textural properties. Goat's milk set yoghurts were produced from milk heated at 72 °C/30 s and 90 °C/5 min, without (G72 and G90) and with mTGase (G72TG and G90TG) and starter culture addition. Protein profiles of goat's milks and yoghurts were also examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Yoghurts were evaluated for rheological properties, texture, microbiological and sensory profile over 2 weeks to study the influence of mTGase, pasteurization and storage.

RESULTS

The enzyme caused significant increases of storage moduli at the end of fermentation: 8.32 ± 0.27 Pa (G90TG) and 2.89 ± 0.18 Pa (G72TG) vs. 6.13 ± 0.07 Pa (G90) and 1.27 ± 0.18 Pa (G72) without enzyme. Lower loss tangent values indicated the enhanced elastic character of the gels with enzyme. Enzyme increased yoghurt's firmness from 49.69 ± 2.61 g (G90) to 60.81 ± 5.29 g (G90TG) after 1 day and from 58.21 ± 0.53 g (G90) to 80.45 ± 0.59 g (G90TG) after 15 days' storage. Enzyme improved starter bacteria survivability during storage of G72TG yoghurt.

CONCLUSION

mTGase can be used simultaneously with the starter culture to improve the rheological properties and texture of goat's milk yoghurt, without deteriorating effect on its flavour. © 2021 Society of Chemical Industry.

Role of fermented goat milk as a nutritional product to improve anemia

Goat milk, like cow milk, needs some modifications to be used as the sole source of nutrition during early infancy. For goat milk to be more like human milk and more nutritionally complete, sugar, vitamins and minerals need to be added to it and for reduction of renal solute load, it needs to be diluted. To prevent megaloblastic anemia in infants fed exclusively on goat milk, folic acid should be supplied either by adding it to goat milk or by an oral folic acid supplement. In fortification of milk products, thermal processing, fermentation, and species differences in milk folate bioavailability are three additional factors that should be considered besides absolute difference in folate concentration between goat and human milk. Whether different feeding regimes (e.g., iron and folate content of diets) influence milk folate content needs to be elucidated by more research. Our findings showed that fermented goat milk during anemia recovery can be improve antioxidant status, protection from oxidative damage to biomolecules, protective effects on testis, improve Fe and skeletal muscle homeostasis as well as improve cardiovascular health. PRACTICAL APPLICATIONS: To be used as part of a postweaning nutritionally well-balanced diet, fermented goat milk is most likely an excellent source of nutrition for the human.

Somatic Cell Number, Physicochemical, and Microbiological Parameters of Raw Milk of Goats During the End of Lactation as Compared by Breeds and Number of Lactations

This study was aimed for the evaluation of somatic cell count (SCC), physicochemical, and microbiological parameters during the end of lactation in the raw milk of Alpine and native Red goat breed. In the experiment, 102 milk samples from Alpine and native Red goats were included. Two different groups within the same breed were analyzed: a group consisting of animals in their first lactation and the second group consisting of animals from the fifth lactation. The milk samples were individually and daily collected during late lactation for three consecutive weeks, and milk fat, protein, lactose, SCC, and total bacteria with enterobacteria were assessed. Fresh milk of goats from late lactation period had a number of somatic cells (SC) within the expected value with log10 of 5.8–6.18 cells/ml for the compared groups. In both breeds, the total mesophilic bacteria were fewer in numbers, however, in the native Red goat, a larger population of such bacteria was enumerated. The number of coliforms and enterobacteria was below 100 cfu/ml. In the current study, we were able to show a significant difference among the studied breeds depending on lactation and season for fat (p = 0.002), but not for lactose and protein content. A positive correlation for total protein (TP), lactose, and fat as well as for lactose and SCC was found in the native Red goat breed. In the Alpine goat breed, a strong positive correlation (0.821^**) was found for lactose and enterobacteria count (EC). In conclusion, these findings evaluate different goat milk parameters during late lactation period and provide an indirect measure to monitor goat mammary gland health for both breeds.

In vitro test to evaluate survival in the gastrointestinal tract of commercial probiotics

The search for functional foods grows constantly, and in this demand, the supply of industries that seek to produce and sell supplements also grows, as is the case of probiotics freely sold in pharmacies and supermarkets. Given a large number of foods with probiotic appeal and supplements sold without the need for a nutritional or medical prescription, this study came up to evaluate the viability of commercial probiotic cells, through in vitro gastrointestinal simulation and analyzing the information present in their labeling. Eleven commercial probiotic samples were analyzed, and viable cell counts were performed before and after in vitro simulation. These products usually use appealing labeling and induce the consumer to purchase these probiotics, which often do not offer the benefits described on the packaging. The results showed that only two samples had the initial concentration indicated on their labeling and four samples offered a concentration of 3 log CFU g⁻¹ in the ileum portion. All samples had a reduction in concentration during the gastrointestinal simulation, which varied from 1 to 4 log CFU g⁻¹, but most do not fulfill the offer of a probiotic supplement, and there should be more inspection and control over the commercialization of this product niche.

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Of eleven probiotics analyzed, only two were in accordance with their labeling.

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Only six probiotics showed an initial concentration above 8 log CFU g-1.

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After gastrointestinal simulation, six probiotics showed viability greater than 6 log CFU g-1.

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Probiotic fermented milk and microorganisms protected by capsules showed the best results.

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Technologies are needed that contribute to maintaining probiotic viability in storage and digestion.

Effect of probiotic Minas Frescal cheese on the volatile compound and metabolic profiles assessed by nuclear magnetic resonance spectroscopy and chemometric tools

This study aimed to evaluate the effect of Lacticaseibacillus casei 01 as a probiotic culture on the production of volatile organic compounds and metabolic profile of Minas Frescal cheese. Lactose (α-lactose and β-lactose), fatty acids (unsaturated and saturated), citric acid, tryptophan, and benzoic acid were the main compounds. Compared with the control cheese, probiotic cheese was characterized by the highest concentration of tryptophan and presented a higher number of volatile acids. The control cheese was characterized by the highest concentration of benzoic acid and fatty acids, resulting in a higher number of volatile alcohols and esters. No differences were observed for α-lactose, β-lactose, and citric acid contents. A clear separation of probiotic and control Minas Frescal cheese was obtained using ¹H nuclear magnetic resonance spectra, demonstrating that the addition of probiotic culture altered the metabolic profile of Minas Frescal cheese. Overall, the findings suggested that the addition of probiotic culture promoted the proteolysis in the fresh cheeses, decreased the lipolysis, and altered the volatile compounds. Furthermore, nuclear magnetic resonance spectroscopy coupled to chemometrics tools could be used to differentiate probiotic and conventional cheeses.

Screening of frozen-thawed conditions for keeping nutritive compositions and physicochemical characteristics of goat milk

Frozen milk can help producers overcome the seasonality of goat milk production, low goat production and short lactation periods, and avoid discarding milk during some special periods. We investigated effects of combination between freezing (cryogenic refrigerator of -16 to -20°C or ultra-cryogenic refrigerator of -76 to -80°C) and thawing (homeothermy of 20 to 25°C or refrigeration of 2 to 4°C) on nutritive compositions and physicochemical characteristics of raw goat milk during storage period (80 d). Compared with fresh goat milk, the frozen-thawed milk decreased contents of fat, protein, and lactose, as well as surface tension and stability coefficient, whereas increased effective diameter and polydispersity index. The average values of color values (L*, a*, and b*) in 4 group samples changed from 83.01 to 82.25, -1.40 to -1.54, 3.51 to 3.81, respectively, and the ΔE of most samples did not exceed 2. In contrast to the other 3 frozen-thawed treatments, goat milk treated with ultra-cryogenic freezing-homeothermic thawing (UFHT) possessed higher fat (5.20 g/100 g), smaller effective particle diameter (0.32 µm), and the lowest polydispersity index value (0.26). The color and confocal laser scanning microscopy images of UFHT were similar to those of fresh goat milk, illustrating UFHT was the optimal approach to maintain the natural quality of goat milk. Our finding provides a theoretical basis for producers to freeze surplus milk.