Evaluating the Quality of Cheese Slices Packaged with Na-Alginate Edible Films Supplemented with Functional Lactic Acid Bacteria Cultures after High-Pressure Processing

The aim of the current study was to assess the efficacy of Na-alginate edible films as vehicles for delivering lactic acid bacteria (LAB) with functional properties to sliced cheeses, with or without high-pressure processing (HPP). A three-strain LAB cocktail (Lactococcus lactis Τ4, Leuconostoc mesenteroides Τ25 and Lacticaseibacillus paracasei Τ26) was incorporated into Na-alginate solution in a final population of 9 log CFU/mL. The cheese slices (without or with HPP treatment at 500 MPa for 2 min) were packaged in contact with the LAB edible films (LEFs), and subsequently vacuum packed and stored at 4 °C. Cheese slices without the addition of films, with or without HPP treatment, were used as controls. In all cases, microbiological, pH and sensory analyses were performed, while the presence and the relative abundance of each strain during storage was evaluated using Random Amplified Polymorphic DNA-PCR (RAPD-PCR). In addition, organic acid determination and peptide analysis were performed using high-performance liquid chromatography. The results showed that in cheeses without HPP treatment, the microbiota consisted mostly of mesophilic LAB and lactococci (>7.0 log CFU/g), while HPP caused a reduction in the indigenous microbiota population of approximately 1−1.5 log CFU/g. In the LEF samples, the populations of mesophilic LAB and lactococci were maintained at levels of >6.35 log CFU/g during storage, regardless of the HPP treatment. Sensory evaluation revealed that the LEF samples without HPP had a slightly more acidic taste compared to the control, whereas the HPP-LEF samples exhibited the best organoleptic characteristics. RAPD-PCR confirmed that the recovered strains were attributed to the three strains that had been entrapped in the films, while the strain distribution during storage was random. Overall, the results of the study are promising since the functional LAB strains were successfully delivered to the products by the edible films until the end of storage.

Characterization of ACE inhibitory and antioxidant peptides in yak and cow milk hard chhurpi cheese of the Sikkim Himalayan region

•

Yak and cow hard chhurpi cheese of Sikkim Himalaya.

•

ACE-inhibitory activities of undigested and GI digested yak and cow hard chhurpi.

•

Bioactive peptides identified by LC-MS/MS peptidomics of yak and cow hard chhurpi.

•

In silico prediction and molecular docking of potential ACE-inhibitory peptides.

In this study, simulated in vitro GI digestion of the Himalayan hard chhurpi cheese resulted in the increase of hydrolyzed protein content, antioxidant and ACE-inhibitory activities. LC-MS/MS-based peptidomics revealed a total of 1473 peptides in the samples originating from different milk proteins, including α-S1-casein, α-S2-casein, β-casein, κ-casein, α-lactalbumin, and β-lactoglobulin, out of which 60 peptides have been reported for different functional properties. A total of 101 peptides were predicted to be antihypertensive using the bioactivity prediction web servers, AHTpin and mAHTPred. In silico molecular docking studies predicted 20 antihypertensive peptides, exhibiting non-bond interactions between hard chhurpi peptides and ACE catalytic residues. A peptide, SLVYPFPGPI, identified in GI digested cow hard chhurpi and undigested, and GI digested samples of yak hard chhurpi, showed a stronger binding affinity towards ACE. Identifying antioxidant and ACE inhibitory peptides in hard cheese products adds value to them as functional foods of the Himalayan region.

A comprehensive review on bioactive peptides derived from milk and milk products of minor dairy species

Abstract

Milk from different species has been exploited for the isolation of various functional ingredients for decades. Irrespective of the source, milk is considered as a complete food, as it provides essential nutrients required by the human body. Proteins and their fractions are valuable sources of bioactive peptides that might exert a health beneficial role in the human body such as immune-modulation, antioxidant activity, ACE-inhibitory activity, anti-neoplastic, anti-microbial, etc. In milk, bioactive peptides may either be present in their natural form or released from their parental proteins due to enzymatic action. The increasing interest in bioactive peptides among researchers has lately augmented the exploration of minor dairy species such as sheep, goat, camel, mithun, mare, and donkey. Alternative to cow, milk from minor dairy species have also been proven to be healthier from infancy to older age owing to their higher digestibility and other nutritive components. Therefore, realizing the significance of milk from such species and incentivized interest towards the derivatization of bioactive peptides, the present review highlights the significant research achievements on bioactive peptides from milk and milk products of minor dairy species.

Graphical abstract

Biotechnological approaches for the production of designer cheese with improved functionality

Cheese is a product of ancient biotechnological practices, which has been revolutionized as a functional food product in many parts of the world. Bioactive compounds, such as peptides, polysaccharides, and fatty acids, have been identified in traditional cheese products, which demonstrate functional properties such as antihypertensive, antioxidant, immunomodulation, antidiabetic, and anticancer activities. Besides, cheese-making probiotic lactic acid bacteria (LAB) exert a positive impact on gut health, aiding in digestion, and improved nutrient absorption. Advancement in biotechnological research revealed the potential of metabolite production with prebiotics and bioactive functions in several strains of LAB, yeast, and filamentous fungi. The application of specific biocatalyst producing microbial strains enhances nutraceutical value, resulting in designer cheese products with multifarious health beneficial effects. This review summarizes the biotechnological approaches applied in designing cheese products with improved functional properties.

Probiotics and prebiotics in non-bovine milk

Probiotics are live microorganisms that, when administered in adequate numbers, confer health benefit/s on the host, while prebiotics are nondigestible food ingredients that are selectively stimulate the growth of beneficial microorganisms in the distal parts of the host digestive tract conferring health benefits. Dairy products manufactured mainly using bovine milk is the major vehicle in delivering probiotics to humans. At present, there is an increasing demand for non-bovine probiotic milk products. Both bovine and non-bovine dairy products contain several ingredients with prebiotic properties such as oligosaccharides that could positively interact with probiotics to alter their functional properties. Furthermore, these bovine and non-bovine products could be fortified with prebiotics from various sources such as inulin and oligofructose in order to provide additional health benefits. In addition, non-bovine milk products are good sources for isolating novel potential probiotics. Non-bovine milk such as goat, sheep, camel and donkey have been used in producing several probiotic products including set-yoghurt, drinking-yoghurt, stirred-yoghurt, ice cream and cheese. Prebiotic inclusions in non-bovine milk at present is mainly associated with goat and sheep milk products. In this context, this chapter focuses on the different types of non-bovine milk products containing probiotics and prebiotics, and product quality and microbiological characteristics with special reference to probiotic viability.

Effect of fortification with calcium from eggshells on bioavailability, quality, and rheological characteristics of traditional Polish bread spread

Hen eggshells are a rich and natural source of calcium and can serve as a biofunctional food ingredient. Enriching the traditional Polish bread spread (sersmażony) with micronized eggshell is an attractive proposition for consumers who require easily available calcium. The present study aimed to evaluate the use of micronized eggshells as a source of bioavailable calcium in bread spread. The study evaluated the effect of selected biocomponents on calcium bioavailability by using an in vitro digestion model. The enrichment of bread spread with eggshell, lysine, vitamin D₃, and vitamin K enhanced all examined physicochemical variables except water activity. Enrichment with eggshells increased calcium levels >2.5-fold compared with the control sample. As an ingredient of bread spread, lysine is an important rheological factor. The bioavailability of calcium was higher in samples with lysine and vitamin K compared with samples that contained eggshell alone.

Fatty acids and fat-soluble vitamins in ewe's milk predicted by near infrared reflectance spectroscopy. Determination of seasonality

The aim of the present work was to determine the fatty acid and fat-soluble vitamin composition and the season of ewe's milk production using NIR spectroscopy. 219 ewe's milk samples from different breeds and feeding regimes were taken each month over one year. Fatty acids were analyzed by gas chromatography, and retinol and α-, and γ-tocopherol by liquid chromatography. The results showed that the quantification was more accurate for the milk dried on paper, except for vitamins. Calibration statistical descriptors on milk dried on paper were good for capric, lauric, myristic, palmitoleic, stearic and oleic acids, and acceptable for caprilic, undecanoic, 9c, 11tCLA, ΣCLA, PUFA, ω3, ω6, retinol and α-tocopherol. The equations for the discrimination of seasonality was obtained using the partial least squares discriminant analysis (PLSDA) algorithm. 93% of winter samples and 89% of summer samples were correctly classified using the NIR spectra of milk dried on paper.

Sensory Profile and Consumers' Liking of Functional Ovine Cheese

The present research was undertaken to evaluate the sensory profile and consumers' liking of functional ovine cheese containing probiotic cultures. Ovine cheese was made from ewe's milk by animals reared in extensive conditions; cheesemaking trials were performed by using rennet paste containing probiotic cells. Experimental cheeses were denoted: cheese manufactured using lamb rennet paste without probiotic (C), cheese manufactured using lamb rennet paste containing a mix of Bifidobacterium lactis and Bifidobacterium longum (BB), and cheese manufactured using lamb rennet paste containing Lactobacillus acidophilus (LA). Ovine cheese containing probiotic strains highlighted a more intense proteolysis and a greater level of short chain free fatty acids and conjugated linoleic acid due to the metabolic activity of the adjunct microflora. The sensorial profile of ovine cheese showed lower humidity and gumminess in cheeses containing probiotics as a consequence of differences in the maturing process; furthermore, probiotic cheeses scored higher ratings for salty and pungent attributes. An interaction effect of probiotic, gender, and age of the consumers was detected in the perceived and the expected liking. The higher rate of expected liking in all experimental cheeses is attributed to the information given, regarding not only the presence of probiotic strains but also the farming conditions and cheesemaking technology.