The Influence of the Addition of Hemp Press Cake Flour on the Properties of Bovine and Ovine Yoghurts.

Hemp press cake flour (HPCF) is a by-product of hemp oil production rich in proteins, carbohydrates, minerals, vitamins, oleochemicals, and phytochemicals. The purpose of this study was to investigate how the addition of HPCF to bovine and ovine plain yoghurts at concentrations of 0%, 2%, 4%, 6%, 8%, and 10% could change the physicochemical, microbiological, and sensory properties of the yoghurts, focusing on the improvement of quality and antioxidant activity, and the issue of food by-products and their utilisation. The results showed that the addition of HPCF to yoghurts significantly affected their properties, including an increase in pH and decrease in titratable acidity, change in colour to darker, reddish or yellowish hue, and a rise in total polyphenols and antioxidant activity during storage. Yoghurts fortified with 4% and 6% HPCF exhibited the best sensory properties, thus maintaining viable starter counts in the yoghurts during the study period. There were no statistically significant differences between the control yoghurts and the samples with 4% added HPCF in terms of overall sensory score while maintaining viable starter counts during the seven-day storage. These results suggest that the addition of HPCF to yoghurts can improve product quality and create functional products and may have potential in sustainable food waste management.

What is the impact of amino acid mutations in the primary structure of caseins on the composition and functionality of milk and dairy products?

The impact of amino acid mutations within the peptide structure of bovine milk protein is important to understand as it can effect processability and subsequently effect its physiological properties. Genetic polymorphisms of bovine caseins can influence the chemical, structural, and technological properties, including casein micelle morphology, calcium distribution, network creation upon gelation, and surface activity. The A1 and A2 genetic variants of ß-casein have recently acquired growing attention from both academia and industry, prompting new developments in the area. The difference between these two genetic variants is the inclusion of either proline in ß-casein A2 or histidine in ß-casein A1 at position 67 in the peptide chain. The aim of this review was to examine the extent to which milk and ingredient functionality is influenced by ß-casein phenotype. One of the main findings of this review was although ß-casein A1 was found to be the dominant variant in milks with superior acid gelation and rennet coagulation properties, milks comprised of ß-casein A2 possessed greater emulsion and foam formation capabilities. The difference in the casein micelle assembly, hydrophobicity, and chaperone activity of caseins may explain the contrast in the functionality of milks containing ß-casein from either A1 or A2 families. This review provides new insights into the subtle variations in the physicochemical properties of bovine milks, which could potentially support dairy producers in the development of new dairy products with different functional properties.

Properties of sodium caseinate as affected by the ß-casein phenotypes.

The aim of the study was to investigate the properties of sodium caseinate dispersions and oil-in-water emulsions obtained from cows' milk of either A1/A1, A1/A2, or A2/A2 ß-casein phenotype. Protein structural characterisation was examined using Fourier Transform Infrared and Nuclear Magnetic Resonance spectroscopies, with physicochemical and interfacial properties assessed by analysing adsorbed protein content, hydrophobicity, solubility, and emulsion stability of the samples. Results showed variations in the secondary structure of all samples dependent of the presence of A1 or A2 ß-caseins. The main differences included greater amounts of α-helix and ß-sheet in A1/A1 and A1/A2 sodium caseinate dispersions that influenced their lower solubility, while random coils/polyproline II helixes were found only in A2/A2 sodium caseinate dispersion. In contrast, upon adsorption on the interface of A2/A2 sodium caseinate emulsion, the protein adopted ordered conformational motifs. This conformational shift supposedly arose from structural differences between the two ß-casein proteoforms, which most likely enhanced the emulsion properties of A2/A2 sodium caseinate compared to either A1/A1 or A1/A2 sodium caseinates. The A2 ß-casein in both, A1/A2 and A2/A2 sodium caseinates, appears to be able to more rapidly reach the oil droplet surface and was more efficient as emulsifying agent. The current results demonstrated that the conformational rearrangement of proteins upon adsorption to emulsion interfaces was dependent not only on hydrophobicity and on solubility, but also on the conformational flexibility of A1/A1, A1/A2, and A2/A2 ß-casein phenotypes. These findings can assist in predicting the behaviour of sodium caseinates during relevant industrial processing.

Pomegranate peel extract - A natural bioactive addition to novel active edible packaging.

The pomegranate (Punica granatum L.) fruit peel has been renowned for containing high amounts of bioactive phenolic and flavonoid compounds; however, it has been commonly deemed as an agricultural waste product. The present study comprehensively reviews the impact of pomegranate peel extract as an active addition to different edible packaging materials. This review provides an overview of the recent trends and advances in active edible packaging materials enriched with pomegranate peel and their technological properties. Recently, significant advances have been made to extend the shelf life of perishable food and control the release and transport of nutraceuticals and bioactive molecules by using pomegranate fruit and its underutilized components. Pomegranate peel extract within the edible matrix provide good compatibility between peel particles and the matrix, and can enhance structural, mechanical, and biochemical properties such as antioxidant and phenolic content as well as antimicrobial activity. The addition of pomegranate peel extract in an edible matrix and applied to food products could also assist in the retardation of natural pigments, lipid oxidation, microbial contamination and influence shelf life by sustaining organoleptic properties of food products. However, more studies are needed to investigate practical implications related to the effects of pomegranate peel extract on the optical, physical and barrier properties of edible films and coatings.

Effect of Ultrasound Treatment on Barrier Changes of Polymers before and after Exposure to Food Simulants.

In this study, we investigated the impact of ultrasound treatment on barrier properties of linear low-density polyethylene (LLDPE) and acrylic/poly(vinylidene chloride) polypropylene (PPAcPVDC)-coated pouches intended for food packaging before and after exposure to food simulants. Packaging pouches were filled with two food simulants, namely ethanol (10% (v/v)) and acetic acid (3% (w/v)), in order to simulate food−packaging interaction and possible compound migration from packaging materials. Samples were subjected to an ultrasound water bath treatment for 5 min, 15 min, and 30 min at 60 °C (±2 °C) and with an amplitude of 100% as an equivalent to the heat-treatment conditions combined with an ultrasound effect. Furthermore, the effect of temperature on the polymer barrier (water vapour and oxygen permeability) properties was tested at 20 °C, 40 °C, and 60 °C. Results showed that PPAcPVDC possessed better properties of water vapour permeability and oxygen permeability properties to LLDPE. Statistical analyses showed a significant (p < 0.001) impact of ultrasound treatment on the overall migration value, regardless of the food simulant used.

Structural Changes of ß-Casein Induced by Temperature and pH Analysed by Nuclear Magnetic Resonance, Fourier-Transform Infrared Spectroscopy, and Chemometrics.

This study investigated structural changes in ß-casein as a function of temperature (4 and 20 °C) and pH (5.9 and 7.0). For this purpose, nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy were used, in conjunction with chemometric analysis. Both temperature and pH had strongly affected the secondary structure of ß-casein, with most affected regions involving random coils and α-helical structures. The α-helical structures showed great pH sensitivity by decreasing at 20 °C and diminishing completely at 4 °C when pH was increased from 5.9 to 7.0. The decrease in α-helix was likely related to the greater presence of random coils at pH 7.0, which was not observed at pH 5.9 at either temperature. The changes in secondary structure components were linked to decreased hydrophobic interactions at lower temperature and increasing pH. The most prominent change of the α-helix took place when the pH was adjusted to 7.0 and the temperature set at 4 °C, which confirms the disruption of the hydrogen bonds and weakening of hydrophobic interactions in the system. The findings can assist in establishing the structural behaviour of the ß-casein under conditions that apply as important for solubility and production of ß-casein.

Edible packaging: Sustainable solutions and novel trends in food packaging.

Novel food packaging techniques are an important area of research to promote food quality and safety. There is a trend towards environmentally sustainable and edible forms of packaging. Edible packaging typically uses sustainable, biodegradable material that is applied as a consumable wrapping or coating around the food, which generates no waste. Numerous studies have recently investigated the importance of edible materials as an added value to packaged foods. Nanotechnology has emerged as a promising method to provide use of bioactives, antimicrobials, vitamins, antioxidants and nutrients to potentially increase the functionality of edible packaging. It can act as edible dispensers of food ingredients as encapsulants, nanofibers, nanoparticles and nanoemulsions. In this way, edible packaging serves as an active form of packaging. It plays an important role in packaged foods by desirably interacting with the food and providing technological functions such as releasing scavenging compounds (antimicrobials and antioxidants), and removing harmful gasses such as oxygen and water vapour which all can decrease products quality and shelf life. Active packaging can also contribute to maintaining the nutritive profile of packaged foods. In this review, authors present the latest information on new technological advances in edible food packaging, their novel applications and provide examples of recent studies where edible packaging possesses also an active role.

The effect of barrier properties of polymeric films on the shelf-life of vacuum packaged fresh pork meat.

The aim of this study was to investigate the permeability properties of synthetic polymeric materials and their influence on the quality of packed chilled pork. Barrier properties of biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex), were tested on three gases: oxygen, carbon dioxide and nitrogen at different temperatures: 4 °C, 20 °C, 40 °C and 60 °C. Coefficients of permeability, diffusion and solubility were determined. The quality parameters of vacuum packed fresh chilled pork stored under controlled temperature over a 21-day period were evaluated with physico-chemical, sensory and microbiological analyses. Results showed that BOPPAcPVDC film provided better protection for fresh pork than BOPPcoex film in terms of physico-chemical, sensory and microbiological attributes, due to its greater barrier behaviour, with smaller permeance data (q) (0.98 to 324 cm3/m2 · d · bar) for BOPPAcPVDC, compared to BOPPcoex (227 to 6200 cm3/m2 · d · bar), in the temperature range from 4 °C to 60 °C (p < .001). The shelf life of fresh pork packed in this film was doubled, from 7 to 14 days.