Human milk (HM) constitutes the first immunological barrier and the main source of nutrients and bioactive components for newborns. Immune factors comprise up to 10% of the protein content in HM, where antibodies are the major components (mainly IgA, IgG, and IgM). In addition, antibacterial enzymes such as lysozyme and immunoregulatory factors such as soluble cluster of differentiation 14 (sCD14) and transforming growth factor β2 (TGF-β2) are also present and play important roles in the protection of the infant's health. Donor milk processed in HM banks by Holder pasteurization (HoP; 62.5°C, 30 min) is a safe and valuable resource for preterm newborns that are hospitalized, but is reduced in major immunological components due to thermal inactivation. We hypothesized that high hydrostatic pressure (HHP) and high-pressure homogenization (HPH) are 2 processes that can be used on HM to reduce total bacteria counts while retaining immunological components. We studied the effects of HHP (400, 450, and 500 MPa for 5 min applied at 20°C) and HPH (200, 250, and 300 MPa, milk inlet temperature of 20°C) applied to mature HM, on microbiological and immunological markers (IgA, IgG, IgM, sCD14, and TGF-β2), and compared them with those of traditional HoP in HM samples from healthy donors. The HHP processing between 400 and 500 MPa at 20°C reduced counts of coliform and total aerobic bacteria to undetectable levels (<1.0 log cfu/mL) while achieving approximately 100% of immunological component retention. In particular, comparing median percentages of retention of immunological components for 450 MPa versus HoP, we found 101.5 versus 50.5% for IgA, 89.5 versus 26.0% for IgM, 104.5 versus 75.5% for IgG, 125.0 versus 72.5% for lysozyme, 50.6 versus 0.1% for sCD14, and 88.5 versus 61.1% for TGF-β2, respectively. Regarding HPH processing, at a pressure of 250 MPa and inlet temperature of 20°C, the process showed good potential to reduce coliforms to undetectable levels and total aerobic bacteria to levels slightly above those obtained by HoP. The median percentages of retention of immunological markers for HPH versus HoP were 71.5 versus 52.0%, 71.0 versus 27.0%, 104.0 versus 66.5%, and 30.9 versus 0.2%, for IgA, IgM, IgG, and sCD14, respectively; results did not significantly differ for lysozyme and TGF-β2. The HPH at 300 MPa produced higher inactivation of immunological components, similar to values achieved with HoP.

This study aimed to evaluate the fatty acid (FA) profile in milk from commercial farms with varying pasture levels in the diet during spring and fall, and to investigate the physical and chemical properties of butter to assess the impact of FAs on technological and nutritional properties. Milk sampling was conducted biweekly from six farms, categorized into high (HP) and low (LP) pasture treatments based on pasture intake: >60% and <35%, respectively. Butter was made from a pasture-based system (GRZ) and a confined system (C). No differences were observed in milk fat percentage between HP and LP in either season. High pasture had 85–66% more conjugated linoleic acid (CLA, p = 0.01), 74–48% more trans-vaccenic acid (TVA, p = 0.01), and 21–15% more branched-chain FAs (BCFAs, p = 0.006) than LP in spring and fall, respectively. In fall, butter from C had lower saturated FAs (SFAs, p = 0.005), higher unsaturated FAs (UFA, p = 0.008), and a lower spreadability index (SI, p = 0.005) than GRZ, resulting in softer butter. In conclusion, HP in both seasons had higher contents of FAs considered healthy for consumers compared to LP. Contrary to expectations, in fall, C showed higher UFAs and lower SFAs in butter, leading to better technological characteristics than GRZ.

The growing incidence of non-communicable diseases makes the search for natural sources of bioactive compounds a priority for such disease prevention/control. Achyrocline satureioides (‘marcela’), a plant rich in polyphenols and native to Brazil, Uruguay, Paraguay, and Argentina, could be used for this purpose. Data on its antidiabetic/antiobesity properties and cellular uptake of bioactive compounds are lacking. The potentiality of non-thermal technologies such as high-hydrostatic pressure (HP) to enhance polyphenol extraction retains attention. Thus, in the present study aqueous and ethanolic marcela extracts with/without assisted-HP processing were chemically characterized and assessed for their in vitro antioxidant capacity, antidiabetic and antiobesity activities, as well as cellular cytotoxicity and uptake on intestinal cell monolayers (TC7-cells, a clone of Caco-2 cells). Aqueous and ethanolic conventional extracts presented different polyphenolic profiles characterized mainly by phenolic acids or flavonoids, respectively, as stated by reverse phase-high-performance liquid chromatography (RP-HPLC) analyses. In general, ethanolic extracts presented the strongest bioactive properties and HP had none or a negative effect on in vitro bioactivities comparing to conventional extracts. TC7-cell viability and cellular uptake demonstrated in conventional and HP-assisted extracts, highlighted the biological effects of marcela bioactive compounds on TC7-cell monolayers. TC7-cell studies showed no HP-induced cytotoxicity. In sum, marcela extracts have great potential as functional ingredients for the prevention/treatment of chronic diseases such as diabetes.

Summary: The study evaluated the effect of 2 feeding strategies, fixed grass (GFix) and maximized grass (GMax), on the fatty acid composition of milk obtained from North American (NAHF) and New Zealand (NZHF) Holstein-Friesian cows, determined by gas chromatography of the derivatized milk fat extract. The results showed that there is a significant correlation between grass intake and fatty acid relative concentration, which affects health and technological indices.

Ionic conditions affect the denaturation and gelling of whey proteins, affecting the physical properties of foods in which proteins are used as ingredients. We comprehensively investigated the effect of the presence of commonly used emulsifying salts on the denaturation and gelling properties of concentrated solutions of β-lactoglobulin (β-LG) and whey protein isolate (WPI). The denaturation temperature in water was 73.5°C [coefficient of variation (CV) 0.49%], 71.8°C (CV 0.38%), and 69.9°C (CV 0.41%) for β-LG (14% wt/wt), β-LG (30% wt/wt), and WPI (30% wt/wt), respectively. Increasing the concentration of salts, except for sodium hexametaphosphate, resulted in a linear increase in the denaturation temperature of WPI (kosmotropic behavior) and an acceleration in its gelling rate. Sodium chloride and tartrate salts exhibited the strongest effect in protecting WPI against thermal denaturation. Despite the constant initial pH of all solutions, salts having buffering capacity (e.g., phosphate and citrate salts) prevented a decrease in pH as the temperature increased above 70°C, resulting in a decline in denaturation temperature at low salt concentrations (≤0.2 mol/g). When pH was kept constant at denaturation temperature, all salts except sodium hexametaphosphate, which exhibited chaotropic behavior, exhibited similar effects on denaturation temperature. At low salt concentration, gelation was the controlling step, occurring up to 10°C above denaturation temperature. At high salt concentration (>3% wt/wt), thermal denaturation was the controlling step, with gelation occurring immediately after. These results indicate that the ionic and buffering properties of salts added to milk will determine the native versus denatured state and gelation of whey proteins in systems subjected to high temperature, short time processing (72°C for 15 s).

The Maillard reaction (MR), under proper environmental conditions, has been used to improve protein functionality. In the present work, 2 high temperatures (50-80°C) and water activity (Aw; 0.45-0.67) were used to promote exogenous glycosylation of glycomacropeptide (GMP) while minimizing processing times (0, 8, 24, 48, and 96 h at 50°C; 0, 2, 4, 8, and 24 h at 80°C). Maltodextrin, a polysaccharide commonly used in the food industry as a functional ingredient, was used as a reducing sugar, and compared with lactose, a native milk sugar. The progression of MR was evaluated by tracking changes in molecular weight using SDS-PAGE, the formation of Amadori compounds, and browning. Aqueous glycosylated GMP solutions (5 to 20% wt/vol) were tested for solubility, rheological properties, and foam formation. As expected, MR progression was faster with Aw = 0.67 and 80°C. Glycosylated GMP powders showed no change in their solubility after MR. However, the apparent viscosity (γ˙=30s^-1) of the 20% wt/vol suspensions exhibited a slight increase when GMP was glycosylated with maltodextrin for 24 h at 80°C, and a 2-log increase when GMP was glycosylated with lactose, with a high browning development in both cases. The foam expansion index of the resuspended glycosylated powders was increased by between 25 and 66% compared with the nonglycosylated powders. Better foam stability (approximately 2 h) and no browning development were observed for GMP glycosylated with maltodextrin for 2 h at Aw = 0.67 and 80°C. The results show that GMP has undergone further glycosylation by means of controlled MR, which improves viscosity and foaming index without negatively affecting solubility. These preliminary studies provide a basis for the future creation of a new ingredient with GMP and reducing sugars.