Background and objectives: Many studies indicate that the maternal diet is an important factor affecting human milk composition. Human milk composition among lactating women in Latvia, as well as the maternal diet during lactation, has not been sufficiently studied. The aim of this research was to assess dietary habits and macronutrient intake among lactating women in Latvia and to examine the effect of diet on human milk composition. Materials and Methods: Research was conducted between November 2016 and December 2017. Mature human milk samples (n = 61) along with a 72h food diary, a food frequency questionnaire (FFQ), and a questionnaire about maternal and infant characteristics were obtained from voluntary women who were recruited via an invitation published in a social media member group for nursing mothers. Fat content in human milk was determined by LVS ISO 2446:2008, protein content was determined by LVS EN ISO 8968-1:2014, lactose was determined by ISO 22662:2007, and the fatty acid profile was analyzed using gas chromatography. Dietary data were evaluated using the Finnish food composition database Fineli, release 19 (3 March 2018). Results: Median values for fat, protein, and lactose in mature human milk were 4.40%, 1.08%, and 6.52%, respectively. Predominant fatty acids in human milk were oleic acid (C18:1 n9c), palmitic acid (C16:0), and linoleic acid (C18:2 n6c) at 34.60%, 24.00%, and 11.00% of total fatty acids, respectively. The trans elaidic acid (C18:1 n9t) level was <0.10% in all human milk samples. Significant, positive associations (p < 0.05) were found between maternal dietary intake of linoleic, α-linolenic, docosahexaenoic, total cis-monounsaturated, total cis-polyunsaturated, and total n-6 and n-3 polyunsaturated fatty acids, the ratio of n-6/n-3, and the level of these fatty acids in human milk. Total energy and carbohydrate intake among participants were lower, but total fat, saturated fat, and sugar intake were higher than recommended. Protein, linoleic acid, and α-linolenic acid intake were adequate, but docosahexaenoic acid intake was noticeably lower than recommended. Women should be supported with information regarding their nutritional needs during lactation and the possible impact of diet on human milk composition. Conclusion: Macronutrient (fat, protein, and lactose) content in human milk is not affected by maternal diet. Conversely, the human milk fatty acid profile is affected by the immediate diet consumed by the mother. Habitual dietary habits can also impact the fatty acid profile of human milk.

Lactobionic acid is a high value added compound industrially produced through energy intensive chemical synthesis, which uses costly metal catalysts, like gold and platinum. In the next years, biotechnological production of lactobionic acid can be supposed to take the full transition to the manufacturing stage. Productivity of lactobionic acid by microbial production can be affected by various factors-choice of microorganism and its concentration, supply of oxygen, temperature, substrate, cultivation method, pH and aeration rate. The aim was to review research findings for lactobionic acid production as well innovative and efficient technology solutions for self-costs reducing. Whey was recommended as a cheap and suitable substrate for the lactobionic acid production. Whey processing has been advised with Pseudonomas teatrolens in 28 °C and in pH 6 to 7 for yielding the highest productivity. The increasing commercial importance urges the progression of schemes for lactobionic acid biotechnological manufacturing.

BackgroundDocosahexaenoic acid (DHA) is an essential fatty acid required for proper growth and development. DHA levels in breast milk vary worldwide. Higher levels are observed among coastal populations and are associated with marine food consumption. Latvia is located in Northern Europe, on the eastern shore of the Baltic Sea. Nevertheless, fish consumption among women of reproductive age is low. The aim of this study was to determine DHA levels in breast milk among lactating women in Latvia.MethodsInvitation to participate in the study was posted on a social media member group for breastfeeding mothers. In total, 71 women were enrolled from November 2016 until December 2017. DHA levels (% of total fatty acids) in breast milk were measured by gas chromatography. Information about food consumed during the three consecutive days prior to the milk sampling was obtained and a food frequency questionnaire (FFQ) was completed. Information about maternal and infant characteristics, current breastfeeding pattern and milk expression method was also collected.ResultsThe mean age of participants was 31 ± 4 years and the mean BMI was 22.1 ± 3.2. 27 participants were primiparas. The average age and birth weight for infants (34 males, 33 females) was 6 ± 4 months and 3.46 ± 0.55 kg, respectively. The median DHA level in breast milk (n = 60) was 0.30 ± 0.18% of total fatty acids and it was not influenced by any of the maternal or infant’s characteristics nor current breastfeeding pattern or milk expression manner (p > 0.05). Fish intake was a positive predictor for DHA levels in breast milk (r = 0.318, p = 0.013). Average maternal DHA intake was 136 ± 26, 137 ± 33 and 178 ± 49 (SEM – standard error of the mean) mg, for the third, second and last day prior to sampling day, respectively.ConclusionsDHA levels in breast milk among lactating women in Latvia correspond to the suggested target DHA value in breast milk (0.30%). Fish consumption is a significant positive predictor for DHA levels in breast milk, however, daily DHA intake among the participants was lower than recommended (200 mg).

Background: Zinc is an indispensable element, being involved in many biological processes. Correspondingly, insufficient zinc intake in early youth can detrimentally affect the function of a growing body. The aim of this study was to determine zinc content in breast milk among lactating women in Latvia and factors (maternal diet; mother’s and baby’s characteristics; breastfeeding pattern) affecting it. Methods: In total, 62 mature milk (at least one month postpartum) samples were collected and pooled within 24 h. Zinc content (mg 100 mL−1) was determined using inductively coupled plasma mass spectrometry (ICP-MS; Agilent 7700×, Agilent Technologies, Tokyo, Japan). Results: Zinc content in mature breast milk ranged from 0.01 to 0.34 mg 100 mL−1 with a median (interquartile range) content of 0.10 (0.05–0.15) mg 100 mL−1. Time postpartum was a significant negative predictor for zinc content in breast milk (r = −0.500; p = 0.000). Median maternal zinc intake was 10.70 (7.24–15.27) mg. Yet, zinc content in breast milk was unaffected by maternal dietary zinc intake (r = 0.155; p = 0.221). Conclusions: Maternal dietary zinc intake was nearly the recommended intake for lactating women (11 mg), but due to low zinc content in breast milk, babies in Latvia might not receive sufficient zinc intake. Future research should aim for the assessment of zinc status by evaluating plasma or serum levels of both mothers and babies.

β-Galactosidase (EC 3.2.1.23) is one of the widely used enzymes for lactose-free milk production and whey permeate treatment. Enzymes can be obtained from microorganisms, plants and animals. Nowadays, microorganisms are becoming an important source for production of commercially available enzymes, which are of great interest and offer several advantages such as easy handling and high production yield. The aim of this review was to summarize findings of research articles on the application of commercially available β-galactosidase preparates in dairy industry, to analyse and compare the most suitable β-galactosidase commercial preparates for lactose hydrolysis. The results showed that the main factor to choose an appropriate β-galactosidase for lactose hydrolysis was reaction condition. Enzymes from microorganisms contain a wide range of optimal pH from 4.0 (Penicillium simplicissimum and Aspergillus niger) to 8.5 (Bacillus subtilis). The greatest commercial potential have enzymes obtained from fungi (Aspergillus oryzae and Aspergillus niger) and yeasts (Kluyveromyces lactis and Kluyveromyces fragilis). Fungal origin enzymes are more suitable for the hydrolysis of lactose in acid whey due to its acidic pH but yeasts origin enzymes for milk and sweet whey. In the study, commercial preparates from different suppliers with the purpose to analyse their lactose hydrolysis potential and give more detailed characteristics of each preparate advantages and drawbacks were also summarized.