Short communication: Determination of lactoferrin in Feta cheese whey with reversed-phase high-performance liquid chromatography

Abstract In the current paper, a method is introduced to determine lactoferrin in sweet whey using reversed-phase HPLC without any pretreatment of the samples or use of a separation technique. As a starting point, the most common HPLC protocols for acid whey, which included pretreatment of the whey along with a sodium dodecyl sulfate-PAGE step, were tested. By skipping the pretreatment and the separation steps while altering the gradient profile, different chromatographs were obtained that proved to be equally efficient to determine lactoferrin. For this novel 1-step reversed-phase HPLC method, repeatability was very high over a wide range of concentrations (1.88% intraday to 5.89% interday). The limit of detection was 35.46μg/mL [signal:noise ratio (S/N)=3], whereas the limit of quantification was 50.86μg/mL (S/N=10). Omitting the pretreatment step caused a degradation of the column's lifetime (to approximately 2,000 samples). As a result, the lactoferrin elution time changed, but neither the accuracy nor the separation ability of the method was significantly influenced. We observed that this degradation could be easily avoided or detained by centrifuging the samples to remove fat or by extensive cleaning of the column after every 5 samples

CASEIN & WHEY PROTEINS IN HUMAN HEALTH

Casein and whey proteins have various functionalities on human health. These are expressed mainly through the peptides that are rereased when these proteins are digested and include antithrombotic & antihypertasive action, positive effects on human nervous system and stimulative effect on human immune system, antimicrobial action and controlling effects on chronic diseases. Furthermore, an intensive research effort has come up to use casein and whey proteins for the production of functional peptides usefull for human health. This contribution reviews the discovered effects of casein and whey proteins on human health and the techniques used to isolate bioactive peptides from them

Characterization of bacterial microbiota of P.D.O. feta cheese by 16s metagenomic analysis

Background: The identification of bacterial species in fermented PDO (protected designa-tion of origin) cheese is important since they contribute significantly to the final organoleptic prop-erties, the ripening process, the shelf life, the safety and the overall quality of cheese. Methods: Ten commercial PDO feta cheeses from two geographic regions of Greece, Epirus and Thessaly, were analyzed by 16S metagenomic analysis. Results: The biodiversity of all the tested feta cheese samples consisted of five phyla, 17 families, 38 genera and 59 bacterial species. The dominant phylum identified was Firmicutes (49% of the species), followed by Proteobacteria (39% of the species), Bac-teroidetes (7% of the species), Actinobacteria (4% of the species) and Tenericutes (1% of the species). Streptococcaceae and Lactobacillaceae were the most abundant families, in which starter cultures of lactic acid bacteria (LAB) belonged, but also 21 nonstarter lactic acid bacteria (NSLAB) were iden-tified. Both geographical areas showed a distinctive microbiota fingerprint, which was ultimately overlapped by the application of starter cultures. In the rare biosphere of the feta cheese, Zobellella taiwanensis and Vibrio diazotrophicus, two Gram‐negative bacteria which were not previously re-ported in dairy samples, were identified. Conclusions: The application of high‐throughput DNA sequencing may provide a detailed microbial profile of commercial feta cheese produced with pasteurized milk. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Analysis of the major probiotics in healthy women’s breast milk by realtime pcr. Factors affecting the presence of those bacteria

Breast milk has been reported as a bacteria source that affects infant gut microbiota development. The present study utilizes a realtime PCR method to identify Lactobacillus and Bifidobacterium spp. in the breast milk of healthy women and attempts to identify factors affecting those human milk bacteria. Breast milk samples—both colostrum and mature milk—of 100 healthy women, were collected in Greece along with data about the demographic factors and nutritional habits of the volunteers. The colostrum samples were found to have higher percentages of either Bifidobacterium or Lactobacillus (76.9% and 48.6%, respectively) compared to the mature milk samples. For younger women, aged from 18 to 29 years, and women from rural areas, bacteria were detected in higher incidence than for older groups and women in urban areas, respectively. More-over, for high-BMI women, bacteria were detected in lower incidence than for those with normal BMI. Probiotic supplements did not affect the composition of the breast milk-identified bacteria. Various factors such as lactation stage, maternal age, maternal weight, and residential location may contribute to the presence of those species in human milk. RT PCR has significant potential for the microbiological analysis of human milk. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Short communication: Determination of lactoferrin in Feta cheese whey with reversed-phase high-performance liquid chromatography

Abstract In the current paper, a method is introduced to determine lactoferrin in sweet whey using reversed-phase HPLC without any pretreatment of the samples or use of a separation technique. As a starting point, the most common HPLC protocols for acid whey, which included pretreatment of the whey along with a sodium dodecyl sulfate-PAGE step, were tested. By skipping the pretreatment and the separation steps while altering the gradient profile, different chromatographs were obtained that proved to be equally efficient to determine lactoferrin. For this novel 1-step reversed-phase HPLC method, repeatability was very high over a wide range of concentrations (1.88% intraday to 5.89% interday). The limit of detection was 35.46μg/mL [signal:noise ratio (S/N)=3], whereas the limit of quantification was 50.86μg/mL (S/N=10). Omitting the pretreatment step caused a degradation of the column's lifetime (to approximately 2,000 samples). As a result, the lactoferrin elution time changed, but neither the accuracy nor the separation ability of the method was significantly influenced. We observed that this degradation could be easily avoided or detained by centrifuging the samples to remove fat or by extensive cleaning of the column after every 5 samples