Low Lactose Content Research Articles

How to Keep Lactose Avoiders Healthy

A large portion of the world’s population has lactose intolerance. Fundamentally, this condition occurs when the small intestine does not produce enough of the lactase enzyme, which digests the disaccharide lactose in milk. Lactose avoiders might unconsciously decide to limit or exclude milk and dairy products from their diets. This group includes people with lactose intolerance, people with an allergy to milk protein, vegans, and those expressing personal preferences. Lactose avoiders are often self-reported as being milk intolerant. In this review, specific amounts of lactose in different types of milk and milk products are presented. The amounts of micro- and macronutrients in them are compared with the daily requirements established by accepted sources. Foods are suggested that can play vital roles in permanently avoiding lactose-containing dairy products, for example, brussels sprouts, as a good source of vitamin B1; kale, as a source of vitamin K; and cereals at breakfast for vitamin B6. Attention is paid to mature cheeses as they are extremely beneficial for health due to their rich vitamin and elemental compositions, and they are also suitable for people with lactose intolerance due to their low lactose content. This information is rarely provided on packaging. In addition, the current state of labeling for the presence of lactose in food and pharmaceutical products is discussed. The term “hidden lactose” is introduced to include added lactose in unexpected foods, drinks, and even medicines.

Estimation of genetic parameters for production, composition and processability of milk from dairy sheep in a New Zealand flock

ABSTRACT This paper aimed to estimate the heritability and genetic correlations for processability (milk coagulation properties, cheese yield, and heat stability), milk production, and milk composition of dairy sheep in a New Zealand flock. Test-day records from 169 ewes were obtained during the 2021–2022 season. Heritability estimates for yield traits (milk, fat, protein, and lactose yield) were moderate and ranged from 0.33 to 0.38. Whereas heritability estimates for processability traits were lower and ranged from 0.17 to 0.27. The genetic correlations indicated that poorer milk coagulation properties were associated with lower mammary health indicated by higher SCS, higher pH, and lower lactose content. Additionally, a higher ratio of casein to calcium i.e. lower availability of soluble calcium was associated with poorer milk coagulation properties. Higher yields of milk, fat, protein, and lactose were associated, but to a smaller degree, with better MCP. It is proposed that genetic improvement of dairy sheep for higher yields of fat and protein, and for lower SCS, could indirectly improve milk processability for cheese-making. However, it is recommended that larger studies involving more dairy sheep flocks are conducted to validate the present results before developing a selection index for this industry.

Effect of milk stasis on mammary gland involution and the microRNA profile

The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 yr ago. To provide evidence for the existence of one or more autocrine factors, 10 multiparous cows in late lactation were quarter-milked for 7 d. Following this baseline period, the right front quarter of each cow was left unmilked, and the other quarters were milked for 7 d. Before the last milking of that period, milk (mammary secretions) was collected aseptically from both front quarters. After that milking, 250 mL of the collected samples were infused in the cows' respective rear quarters. No quarters were milked for the following 7 d (milk stasis period), and quarter milking was then resumed in all quarters for the last 7 d of the experiment (remilking period). Quarter milk samples were collected during the baseline period, before the milk stasis period, and during the remilking period. These samples were used for measuring milk components and the concentration of involution markers (SCC, BSA, and lactoferrin). Samples of mammary secretions were collected manually from the quarters during the milk stasis period for involution marker determination. We extracted RNA from samples collected from front quarters before the last milking before the milk stasis period for microRNA (miRNA) determination. As anticipated, the longer milk stasis period implemented for the right front quarter resulted in a more advanced involution than in the left front quarter, based on the concentration of involution markers in the mammary secretions, lower milk production recovery, and changes in milk composition during the remilking period. All 3 involution marker concentrations in the mammary secretions increased in both rear quarters, but were greater in the right quarter secretions than in the left quarter secretions. Resuming milking reinitiated milk production in all quarters, but milk production recovery in the right rear quarters was less robust than that in the left rear quarters (54.3 ± 1.4% vs. 61.6 ± 1.4%, respectively). Milk from the quarters infused with mammary secretions (right rear) had a lower lactose content, but a higher milk protein content and higher SCC than the quarters infused with milk. We detected a total of 359 miRNAs, 76 of which were differentially expressed in milk and mammary secretions. Expression of bta-miR-221 and bta-miR-223 was upregulated in mammary secretions 34- and 40-fold, respectively. The results of the present experiment support the contention that milk stasis leads to the accumulation of one or more factors that trigger involution. The results also indicate that milk stasis leads to changes in the miRNA profile of the milk, but whether such changes are a cause or a consequence of the involution process remains to be established.

Impact of cow, buffalo, goat or camel milk consumption on oxidative stress, inflammation and immune response post weaning time

Milk is a whitish liquid that is secreted from mammary glands; and considered as the primary source of nutrition for newborns since they are not able to digest solid food. However, it contains primary nutrients, as well as growth and immune factors. Early weaning is a critical issue that face women and their babies in developing countries. To avoid infant malnutrition, they tend to use other milk types instead of baby formula. Therefore, the present study aimed to evaluate the impact of cow, buffalo, goat or camel milk consumption on oxidative stress, inflammation and immune response in male and female Sprague Dawley rats post weaning time. The amino acids, fatty acids, minerals and vitamins in the tested milk types were evaluated. Animals were divided into 5 groups (control, cow, buffalo, goat and camel milk administrated groups) (10 rats/group); each animal was administrated by 3.4 ml/day. Rats were administered with milk for 6 weeks; at the end of the 5th week, five animals of each group were isolated and the remaining five animals were immunized with sheep red blood cells (SRBCs) and kept for another week to mount immune response. The effect of different milk types on rats’ immune response towards SRBCs was evaluated through pro-inflammatory cytokines, antioxidants, ESR and CRP measurement; together, with the histopathological examination of spleen samples and hemagglutination assay. Camel milk consumption reduced oxidative stress and inflammation in spleen that resulted from SRBCs immunization; in addition to, B cell stimulation that was apparent from the high level of anti-SRBCs antibodies. Camel milk is recommended for newborn consumption, due to its high-water content, unsaturated fatty acids, and vitamin C, as well as low lactose and fat content.

Milk yield and quality at udder quarter level are influenced by quarter position, pathogen, and somatic cell score

There is a paucity of information about milk composition and quality at the quarter level from complete milking of the udder, mainly because of the difficulties of sampling procedures which imply the adoption of a vacuum system connected to four independent buckets. The objective of this study was to evaluate the effect of quarter position, intramammary infection status, and somatic cells on milk yield and composition at the mammary quarter level of Simmental cows. Milk samples were collected during three consecutive days, after milking individual mammary quarters of 10 lactating cows separately, for a total of 120 quarter milk samples. Samples were analysed for composition, somatic cell count (SCC), differential SCC, and bacterial culture. Somatic cell count was log-transformed to somatic cell score (SCS) to achieve normality of distribution. Sources of variation of milk yield and quality traits were investigated using a linear mixed model which included the fixed effects of quarter position (1 to 4), pathogen presence (positive or negative), and SCS class (low, medium-low, medium-high, and high). The interaction between cow and quarter position was included as random effect. Quarter position significantly affected milk yield, with rear udder quarters yielding more milk compared to their front counterparts, but with negligible effects on milk composition. Classes of SCS influenced milk composition, in a way that quarters with high SCS had lower lactose content and higher differential SCC. This study is a contribution towards the possibility to better understand physiological processes at cow udder quarter level.

Localized mammary gland changes in milk composition and venous blood metabolite concentrations result from sterile subclinical mastitis

Subclinical mastitis reduces milk yield and elicits undesirable changes in milk composition, but the mechanisms resulting in reduced milk production in affected mammary glands are incompletely understood. This study investigated the effects of sterile inflammation on mammary gland metabolism by assessing changes in milk and venous blood composition. Mid-lactation primiparous Holstein cows (n = 4) had udder halves randomly allocated to treatments; quarters of 1 udder half were infused with 2 billion cfu of formalin fixed Staphylococcus aureus (FX-STAPH) and quarters of the opposite udder half infused with saline (SAL). Blood samples were collected from the right and left subcutaneous abdominal veins in 2.6 h intervals until 40 h post challenge and analyzed for blood gas and metabolite concentrations. Milk from FX-STAPH udder halves had significantly increased SCS by first milking at 8 h post-challenge. By 16 h post-challenge, FX-STAPH udder halves had increased concentrations of protein and lactate and lower lactose concentrations than SAL udder halves. Milk fat concentrations, milk yields, energy corrected milk yields, and the ferric reducing antioxidant power of milk were not significantly different between SAL and FX-STAPH udder halves. Venous blood of FX-STAPH halves had marginally greater concentrations of saturated O2, partial pressures of O2, and glucose concentrations than SAL halves. Conversely, total and partial pressures of CO2 did not differ between udder half treatments suggesting a shift in local metabolite utilization in FX-STAPH udder halves. These results indicate that changes in milk composition resulting from mastitis are accompanied by changes in some key blood metabolite concentrations. The shift in venous blood metabolite concentrations, along with the marked increase in milk lactate, suggests that local mammary tissue and/or recruited and immune cells alters metabolite usage in mammary tissues. Future studies are needed to quantify the uptake of key milk precursors during mastitis.

Low Lactose Yogurt with Blueberry Jam: Development and Sensory Acceptance

Introduction: The lactose-intolerant public represents an important portion of the population; however, the diversification of products that serve this population is still very limited. Objective: In this bias, this study aimed to develop a low-lactose yogurt added with blueberry jelly, combining sensory and functional characteristics of the fruit. Methods: Different concentrations of β-galactosidase were evaluated in the fermentations, in addition to four formulations of blueberry jelly that were sensorially tested for preference, a formulation was selected and its global acceptance and purchase intent were verified. Results: The use of 1.5 g L- 1 of β-galactosidase allowed for a more significant reduction of lactose during the fermentation process. Of the four jelly formulations tested, the whole fruit was sensory preferred, and the low-lactose two-layer yogurt showed 86% acceptance and 74% purchase intention. Conclusion: It was possible to develop a product with low lactose content and sensorially pleasant to the consumer.

Decreased lactose percentage in milk associated with quarter health disorder and hyperketolactia, a proxy for negative energy balance, in dairy cows

Several studies have described variations in lactose content (LC) in dairy cows during udder quarter health disorder or negative energy balance (NEB). However, their joint effects on LC have never been described. This was the aim of a longitudinal observational study performed on 5 Quebec dairy farms using automatic milking systems. Quarter milk samples were collected every 14 d from 5 to 300 DIM. Quarter health status was described by combining SCC level (SCC- or SCC+: < or ≥100,000 cells/mL) and infectious status (Patho- or Patho+: presence or absence of pathogens on a milk culture). Cows with NEB in early lactation (DIM <70) were identified using milk β-hydroxybutyrate (BHB) content: 0.15 mM = BHB-; 0.15 - 0.19 mM = BHB+; > 0.19 mM = BHB++. A total of 14,505 quarter cisternal milk samples were collected from 380 lactating cows. The quarter LC was analyzed using a mixed linear regression model with the following fixed effects: quarter health status, parity, time interval between last milking and sampling, quarter milk yield (in kg/d), DIM, and herd. A random quarter intercept with a repeated measures correlation structure and a cow random intercept were also specified. The LC of SCC+ quarters was lower (-0.17 ± 0.013% pts) compared with LC of SCC- quarters for both primiparous and multiparous cows. Over the 162 bacterial species identified, only 8 species had a prevalence greater than 4.0%, and just 5 of them were associated with a reduction in LC: Staphylococcus aureus, Staph. chromogenes, Streptococcus dysgalactiae, Staph. epidermidis, and Staph. simulans. Cows identified as BHB+ and BHB++ in early lactation had a lower LC (-0.05 ± 0.019% and -0.13 ± 0.020% pts, respectively) compared with BHB- cows. For BHB++ cows, in both parity groups the decrease in LC (-0.20 ± 0.025% pts) was higher in SCC+ quarters compared with SCC- quarters. Moreover, the additive effect of the quarter health status and NEB on milk LC was greater with larger increases in BHB. Our findings highlight the necessity to jointly take into consideration both quarter health status and milk BHB concentration when using LC as a biomarker for NEB.

Water-soluble oat extract enriched with mango peel flour: preparation, characterization and application in Greek yogurt.

This study aimed to produce water-soluble oat extract enriched with mango peel flour (MPF) as a source of active compounds and to use this ingredient as a partial substitute for whole milk in Greek yogurt (GY) for its nutritional enrichment. Enriched water-soluble oat extracts (EWSOE) were produced with different concentrations of MPF (0%, 1%, 1.5% and 2%) and characterized in relation to pH, titratable acidity, soluble proteins and total phenolics. Three GY formulations were prepared by partially replacing whole milk with EWSOE and the best formulation (in relation to sensory analyzes and phenolics compounds) was selected for storage study, chemical characterization, and sensory acceptance testing. MPF addition increased soluble proteins and total phenolics in EWSOE. GY formulations prepared with EWSOE had similar sensory scores. During storage, GY prepared with EWSOE containing 2% MPF exhibited changes in pH and titratable acidity and a reduction in total phenolics. Color parameters, cholesterol, and fatty acid composition did not change over 21 days of storage. The major fatty acids in GY were oleic and palmitic acids. The selected product had low lactose content (1.2%), achieved satisfactory sensory acceptance in relation to the evaluated attributes, and had lipid (~6.19%) and protein (~3.96%) contents within regulatory requirements. Additionally, EWSOE is a valuable ingredient in GY preparation, offering beneficial nutritional and functional properties.

LACTOSE-FREE ICE CREAM TECHNOLOGY BASED ON SECONDARY DAIRY RAW MATERIALS

Expanding the assortment of lactose-free dairy products, namely, ice cream for people who cannot tolerate lactose is a promising direction of research. The purpose of the work is to develop the technology of milk lactose-free synbiotic yogurt ice cream based on buttermilk protein-lipid concentrate, obtained by ultrafiltration/diafiltration, with the addition of natural flavoring and food additives, and the study of its quality indicators. A protein-lipid concentrate of buttermilk with a low lactose content was obtained by ultrafiltration/diafiltration, and its quality indicators were determined. The concentrate has a high protein content (16.01%) and a low lactose content (1.28%). Protein-lipid concentrate fermented with synbiotic sourdough is the main component included in the formulation of lactose-free synbiotic yogurt ice cream. The main physico-chemical parameters of the obtained fermented protein-lipid concentrate were determined, which ensures a rational content of the main components of the chemical composition in the finished lactose-free ice cream (it does not contain lactose, the protein content is 8.46%) and a high content of useful microflora (bifido- and lactobacilli). A mixture for lactose-free synbiotic yogurt ice cream was obtained according to a scientifically based recipe. A sample of lactose-free ice cream was made from the mixture using traditional technology, and organoleptic, physico-chemical and microbiological quality indicators were investigated. A comparison of the quality indicators of the studied sample with the control, which was taken as classic yogurt ice cream, was carried out. The mass fraction of lactose in samples of lactose-free ice cream is 0,011%. The developed lactose-free synbiotic yogurt ice cream has high probiotic activity (contains lacto- (3.0•108 CFU/g) and bifidobacteria (3.5•109 CFU/g)).

Statistical methods and its applications in Whey protein binding (Bos Taurus)

Milk is made up of two proteins, such as casein (80%) and whey (20%). These proteins, which include membrane globular proteins, glycoproteins, and lipoproteins, are mostly found in the outer layer of milk fat globule membranes. WP can be separated from the casein in milk or formed as a byproduct of cheese making and contains all nine essential amino acids with a low lactose content. Whey protein has many health benefits, including improving strength and body composition, promoting weight loss, boosting metabolism, stifling hunger, maintaining good health, avoiding nourishing the bones, reducing inflammation, promoting quick wound healing, lowering blood pressure, repairing and preserving muscle tissues etc. Many dairy and food-based industries eagerly explore the accurate retention time for the formation of health related new byproducts. As of date, there are very few studies available in the world literature citation database and too many micro and macro studies on WP are currently being undertaken globally, they provide insight into the binding of particular amino acids (Seq. peptides) and their accurate lag time of binding to the formation of "helixes and sheaths. In this paradigm, statistical tool are very important to determine average time and WP algorithms for analysis of seq amino acids and the metabolic pathway's action. Overall, the present research attempts to extrapolate the Seq peptide's binding capacity and its retention time for amino acids in order to fill the aforementioned research gap. For the model demonstration we used the commonly cited whey protein peptide (Seq) NCBS, which was considered to prove the hypothesis. The Markova two state random and Monte Carlo simulation (superimposed artificial neural network) models were formulated to extract transient probabilities and retention times of Seq peptides. As per the results, the binding capacity was found to be excellent with a good retention time (5 to 11.50 minutes) in cross-linked and unlinked cases (10 to 13.50 minutes). Bioinformatics, the dairy industry, and life scientists will find these more recent discoveries to be very helpful for measuring likelihoods and transient probabilities of binding.

EFEK WAKTU AGING DAN PENGERINGAN VAKUM PADA ANALISIS PROKSIMAT DAN TINGKAT ASAM AMINO DARI KEFIR SUSU KAMBING

Goat milk kefir has high nutritional value, especially in protein and calcium content and has a low lactose content. Vacuum drying is an alternative to remove the water content in kefir so that it can extend the shelf life because it inhibits bacterial growth. This study determines the effect of aging time and drying time using vacuum drying method on the characteristics and amino acid composition of goat milk kefir (kefir and powder kefir). Fermented goat milk (24 hours) use kefir grains without aging and with aging times of 1, 2, 3, 4 (week). The total titrated acid and fat content were significantly different in kefir, but it is not significantly different in powder kefir. The yield, moisture, ash, protein, fiber, and fat in both kefir and powder kefir did not show significant differences. The best treatment based on the exponential comparison method for both powder kefir and kefir was 3 weeks of aging time. Therefore, the amino acid components in powder kefir and kefir underwent changes. The highest total amino acids in kefir was kefir without aging. The highest amino acid of powder kefir was obtained after 2 weeks of aging time.

LACTOSE INTOLERANCE

Introduction: Lactose intolerance in children in early childhood has been increasing the level of intolerance, evidencing in the child’s growth and development phases, being vital during the consumption of milk. Presenting symptoms and food discomfort due to the consumption of milk. Lactose intolerance can be classified as primary, when there is an intrinsic defect of the enzyme; or secondary, when there is a damage to the intestinal mucosa with consequent lack of it. Objective: This research aims to describe the conduct of the nutritionist towards children with lactose intolerance in early childhood based on literary reports. Method: Study of integrative literature review, descriptive and exploratory, with the purpose of presenting issues related to nutritional conduct in the care of children in early childhood. For this, information will be selected in other articles, found on search sites: SCIELO, PubMed and Google Scholar. The sample population will be composed of articles recently published between the years 2016 to 2020, and in accordance with the pre-established inclusion and exclusion criteria. The selection will take place in the month of May 2021. Results. It was found among the investigated productions that most of them are about nutritional characteristics, including the concern with calcium deficiency and alternatives to substitute products that develop symptoms by those that have low lactose content. Among the metabolic aspects were not the main focus of the articles found, however, only one article addressed this topic. Conclusions: Therefore, nutritionists play a fundamental role in the improvement and quality of life of children in early childhood, which will collaborate for their growth and healthy development, under the conditions presented, to provide information to parents about diseases and nutritionally adequate substitutes.

Application of Non-Enzymatic Lactate Sensor Modified by Graphitic Carbon Nitride/Iron–Platinum Nanoparticles and Combined With the Low Power Consumption Instrumentation Amplifier and Calibration Readout Circuit

In a previous study, this laboratory produced and tested a lactic acid biosensor using a copper-doped zinc oxide (CZO) sensing film modified with graphite carbon nitride (g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) and iron platinum nanoparticles (FePt NPs). The previous sensor exhibited two non-ideal effects during persistent use and when alternating between high and low lactose concentrations. Using a low unity-gain frequency and low power consumption instrumentation amplifier (UGFPCIA) in conjunction with a calibration readout circuit, it was possible to reduce the previously observed drift and hysteresis effects. The UGFPCIA and calibration readout circuit were connected to a voltage-time (V-T) measurement system so the effects could be accurately quantified. The influence of the UGFPCIA on the measurement characteristics of the lactate biosensor were recorded and compared to a similar device using a commercial LT1167. Results showed that the UGFPCIA produced a more stable measurement, where linearity increased from 0.985 to 0.998. When measuring interference effects, the fluctuation in response voltage became smaller, and the time drift effect was successfully reduced by 89.7%. The hysteresis effect reduced the forward period by 0.13 mV, and the reverse period by 4.37 mV.

Heat treatment of milk protein concentrates affects enzymatic coagulation properties

Dairy ingredients with highly concentrated protein contents are high added value products with expanding market. The manufacture of such ingredients includes a succession of unit operations of which heat treatment is a key step to guarantee the microbial safety, that induces major changes in protein structures and thus ingredients functionalities. However, due to an incomplete understanding of phenomena taking place at high protein concentrations, shedding light on their mechanisms is a scientific challenge as well as an industrial need. In this study, the influence of heat treatment (74 °C/ 30 s) of highly concentrated milk protein systems (up to 20 % w/w) on protein denaturation/aggregation and enzymatic coagulation properties was studied using an original semi–industrial approach. 10 % w/w protein solutions constituted with whey protein and casein micelles at milk ratio, standardized in osmosed water or ultrafiltration permeate were used. These protein solutions were processed in different ways prior the manufacture of powders: heat treatment of the 10 % w/w protein solution before vacuum evaporation, heat treatment of the 20 % w/w protein solution after vacuum concentration, two consecutive heat treatments before and after vacuum evaporation. A fourth powder was prepared from unheated 10 % w/w protein solution. An increase in protein concentration led to a higher heat-induced protein denaturation. This phenomenon was reduced when increasing the lactose content. The effect of heat treatment on the extent of protein denaturation was not cumulative. At high protein concentration, interactions between κ-casein and whey protein were modified compared to milk, as mainly micelle-bound aggregates were formed at pH about 6.7. This phenomenon was enhanced at low ionic strength and lactose content. Our study showed that the enzymatic coagulation properties of reconstituted protein powders could be correlated with their physico–chemical compositions. An increase in protein denaturation disrupted the gel reorganization and led to the formation of weaker gels but did not interfere on the micelles aggregation phase and the early gelation. On the contrary, an increase in ionic strength and lactose content led to higher gel time.

Effect of Tamarillo Fortification and Fermentation Process on Physicochemical Properties and Nutrient and Volatiles Content of Yoghurt.

Bright-red Laird’s Large tamarillo is a unique and under-utilised fruit that is a dietary source of carotenoids, vitamins C and E, and dietary fibre. The effects of the addition of freeze-dried tamarillo powder (5–15%) to milk and yoghurt starter either before (PRE) or after (POS) fermentation on physicochemical properties were examined. Using LC-MS and GG-MS, nutrient and volatile contents of tamarillo yoghurt were also examined. The addition of tamarillo prior to fermentation was associated with a more yellow colour and higher concentrations of tocopherol compared to when tamarillo was added after fermentation. Higher elastic modulus, PUFAs, pro-vitamin A content, and vitamin C retention were observed for POS than PRE. All tamarillo yoghurts showed improvement in syneresis, lower lactose content, and higher concentrations of antioxidant vitamins than the commercial premium-assorted fruits yoghurt from New Zealand Food Composition Data. Yoghurt fortified with tamarillo powder offers the potential for the development of a high-value nutritional product that could be a good source of vitamin C and a source of vitamin E and β-carotene, and maintain the volatiles that give tamarillo its distinctive flavour.

Principles of lactose crystallization and rheology of milk protein concentrate

Milk protein concentrate (MPC) is a commercial designation for dairy ingredients with higher protein and lower lactose content than conventional skim milk powder. Lactose in its amorphous form is found in several spray-dried dairy powders. Amorphous lactose is thermodynamically unstable and can mobilize and crystallize over time under adequate temperature and moisture content. Moisture sorption from the air precedes crystallization, enhancing MPC cohesiveness and caking. This increased humidity results in poor rehydration and dispersibility, lower yield during drying, operation problems, difficulties in handling and storage. Moreover, lactose crystallization in MPC can cause Maillard browning reaction and fat oxidation. To avoid this problem, it is necessary to pre-crystallize lactose as alpha-lactose monohydrate, which is non-hygroscopic, before spray drying. Such a procedure is essential in preventing deterioration of MPC resulting from lactose crystallization or chemical reactions. Additionally, the control of this step is important to obtain specified and reproducible powder, in terms of size and crystallization level. There are various reports on the rheology of milk-based products; however, there is a lack of investigation on concentrated systems. Consequently, the objective of the present work is to review basic concepts of lactose crystallization and rheology of milk protein concentrate.

Influence of goat colostrum and mature milk on intestinal microbiota

In this study, we compared the content of main components in goat colostrum and mature milk, and evaluated their influences on the intestinal microbiota to establish the correlations between milk components and functional features of the intestinal microbiota. Compared with goat mature milk, colostrum had significantly higher contents of protein, fat, minerals, dry matter, EGF, IGF-I, LTF and IgG, but lower concentrations of lactose and cAMP. The metagenomic analysis indicated that ingestion of mature milk increased the abundance of probiotic bacteria Lactobacillus and Muribaculum, while goat colostrum intake could promote the growth of probiotics Lactobacillus and Alistipes, but also the pathogen Helicobacter. Fat content was positively associated with the abundance of Helicobacter. Our study provided evidence that goat colostrum and mature milk could change the composition and structure of the intestinal microbiota community in different ways, which might drive the downstream effects on the host’s metabolism and health.

Lactose and its relationship with other milk constituents, somatic cell count, and total bacterial count

Lactose has an essential role in milk synthesis, and low lactose content adversely affects dairy product yield. In this study, the association between milk lactose content and other milk constituents (protein and fat), somatic cell count (SCC), and total bacteria count (TBC) was valuated using a database of bulk tank milk (BTM) samples from dairy farms in southern Brazil. Factor and cluster analysis were performed on a dataset containing the fat, protein, and lactose contents, SCC, and TBC of 154,781 BTM samples evaluated by the State Laboratory of Milk Quality (LABLEITE). The factor analysis showed that lactose content in milk was positively associated with fat and protein contents as well as negatively associated with SCC and TBC. The cluster analysis on three clusters showed differences in the fat and protein contents of the BTM samples (P<0.0001) that were not associated with lactose content. In cluster 1, an increase in SCC was associated with a reduction in lactose content. In contrast, in cluster 3, a decrease in lactose content was associated with an increase in SCC and TBC. Increases in SCC or TBC is associated with reduction in milk lactose content without influence from variations in fat and protein contents. Additionally, the evaluation of milk total solids, which represents most milk constituents, is suggested for assessment of milk quality.

Біотехнологічні аспекти застосування штамів з β-галактозидазною активністю у виробництві ферментованих молочних продуктів

Subject of study. In the Ukrainian market, most ща fermented dairy products are traditional and ерун фку in great demand among various segments of the population. However, for a certain category of consumers, this segment of dairy products is not recommended for use due to lactase deficiency, which prevents the breakdown and assimilation of lactose containing dairy products. Consumption of dairy products causes discomfort and disorders in the gastrointestinal tract and malaise of such people. This review article is based on the results of basic and applied research of foreign and domestic scientists in this area, it indicates ways to solve this problem and the feasibility of the presence of these products in the diet of this group of people. The aim of the work is a systematic analysis of modern scientific information on the ways to reduce lactose content by the use of fermenting preparations based on strains with β galactosidase activity and integrated use of bacterial cultures and enzyme preparation of β galactosidase in the production of fermented dairy products. Results and discussion. It is shown that there are strains of microorganisms that have a sufficiently high β-galactosidase activity. However, the actual breakdown of lactose occurs in small quantities. The analysis of the literature showed that most often for the production of milk and dairy products with low lactose or lactose-free content, the enzyme lactase is used, which breaks down lactose into individual sugars – glucose and galactose. And the combination of microorganisms and enzyme preparation allows expanding the range of products and meet the needs of lactose intolerant consumers. Scope of research results. The obtained search results will be used in the development of technologies for fermented dairy products with low lactose or lactose-free content.