Physicochemical and sensory properties of goat cheeses and their fatty acid profile in relation to the geographic region of production

Structuration of lipid bases zero-trans and palm oil-free for food applications

This work evaluated structured lipids (SLs) through chemical and enzymatic interesterification (CSLs and ESLs). Blends of soybean oil and peanut oil 1:1 wt% were used, with gradual addition of fully hydrogenated crambe to obtain a final behenic acid concentration of 6, 12, 18, and 24 %. Chemical catalysis used sodium methoxide (0.4 wt%) at 100 °C for 30 min, while enzymatic catalysis used Lipozyme TL IM (5 wt%) at 60 °C for 6 h. Major fatty acids identified were C16:0, C18:0, and C22:0. It was observed that with gradual increase of hard fat, the CSLs showed high concentrations of reaction intermediates, indicating further a steric hindrance, unlike ESLs. Increased hard fat also altered crystallization profile and triacylglycerols composition and ESLs showed lower solid fat, unlike CSLs. Both methods effectively produced SLs as an alternative to trans and palm fats, view to potential future applications in food products.

The Impact of Goat Milk Pretreatment with Pulsed Electric Fields on Cheese Quality

To reduce the microbial load in goat's milk, which is less thermally stable than cow's milk, an alternative processing method was used in this study. This involved treating the milk with pulsed electric fields (PEFs) (at 10 kV·cm-1, with 50 µs pulses for 3 Hz) and then heat-treating it at 63 °C for 6.0 s, as well as using heat treatment alone at 75 °C for 3.4 s. Cheeses were made using both types of milk treatment, and samples were collected after 5, 15, and 25 days of ripening for DNA extraction and purification, followed by high-throughput sequencing on the MiSeq Illumina sequencing platform. Analysis of the bacterial populations in the two types of cheese using various diversity indices revealed no significant differences in species richness and abundance, although there was a trend for the PEF-treated cheese to have a less diverse set of species with an uneven distribution of relative abundance. However, when examining the composition of the microbial communities in the two types of cheese using Weighted UniFrac analysis and Analysis of Similarities, there were significant differences in the presence and abundance of various species, which could have implications for the development of starter cultures. Concerning physicochemical properties (pH, aw, moisture content, total acidity and L, and a and b color parameters), the results also reveal that, generally, no significant differences were found, except for the color parameter, where cheeses treated with PEF demonstrated more whiteness (L) and yellowness (b) during ripening. Sensory scores for typicity (caprylic, goaty, and acetic) increased over time, but between treatments, only small differences were perceived by panellists in cheese with 5 days of ripening. Concerning texture firmness and cohesiveness, the PEF+HT samples presented lower values than the HT samples, even over storage time. In general, concerning quality parameters, similar behavior was observed between the treatments during the ripening period.

Simultaneous Extraction of Bioactive Compounds from Olea europaea L. Leaves and Healthy Seed Oils Using Pressurized Propane

Olive leaves (OL) are products of olive cultivation with a high commercial value because they contain valuable bioactive compounds. Chia and sesame seeds have a high functional value because of their attractive nutritional properties. When combined in the extraction process, the two products constitute a product of high quality. The use of pressurized propane in vegetable oil extraction is advantageous because it provides solvent-free oil. This study aimed to combine two high-quality products to obtain oils with a unique combination of attractive nutritional properties and high levels of bioactive compounds. The mass percentage yields of the OL extracts with chia and sesame oils were 23.4% and 24.8%, respectively. The fatty acid profiles of the pure oils and their respective OL-enriched oils were similar. There was an aggregation of the 35% and 32% (v/v) bioactive OL compounds in chia and sesame oils, respectively. OL oils exhibited superior antioxidant capacities. The induction times of the OL extracts with the sesame and chia oils increased by 73% and 4.4%, respectively. Incorporating OL active compounds in healthy edible vegetable oils using propane as a solvent promotes the reduction of lipid oxidation, improves the lipid profiles and health indices of the oils, and forms a product with attractive nutritional characteristics.

The influence of the texture and color of goat’s salad cheese on the emotional reactions of consumers compared to cow’s milk cheese and Feta cheese

In this study, the sensory and mechanical aspects of the texture of goat’s milk salad cheese were correlated with the emotional profiles of consumers. Using descriptive sensory analysis and instrumental assessment, the texture profile of goat’s milk salad cheese was compared to cow’s milk salad cheese and Feta cheese. Texture measurements confirmed that goat’s cheese compared to cow’s cheese had more softness and less hardness, and Feta cheese had the highest whiteness index compared to the other cheeses. Goat’s milk salad cheese was much less acceptable to consumers compared to cow’s milk cheese and Feta cheese. Consumers also indicated that the hardness of goat’s cheese was lower than that of cow’s cheese and Feta cheese. A reduction in “stickiness” in comparison with cow’s cheese was also reported; however, it was much higher than that for Feta cheese. The “fracturability” and “graininess” of goat’s cheese was similar to cow’s cheese. Emotional profile analysis showed that goat’s cheese evokes mainly negative emotions. Consumers indicated only one positive emotion in the case of this cheese, which was “healthy”. The most frequently mentioned emotions after the consumption of goat’s cheese were “upset”, “disgusted” and “worried”. Many consumers also indicated “disappointed” and “angry”, which did not occur after the consumption of cow’s cheese. This research shows how important it is to combine several analyses and techniques when evaluating dairy products, including salad cheeses. It is also important that consumer research is enriched by emotional profiling.

Graphical abstract

Enrichment of Ewe’s Milk with Dietary n-3 Fatty Acids from Palm, Linseed and Algae Oils in Isoenergetic Rations

Increasing the levels of n-3 fatty acids (FA) in dairy products is an important goal in terms of enhancing the nutritional value of these foods for the consumer. The purpose of this research was to evaluate the effects of linseed and algae oil supplements in ovine isoenergetic diets on healthy milk fatty acid composition, mainly n-3. Seventy-two Churra dairy ewes were divided and randomly assigned to four experimental treatments for 6 weeks. The treatments consisted of a TMR (40:60 forage:concentrate ratio) that varied according to the inclusion of different types of fat (23 g/100 g TMR): hydrogenated palm oil (control), linseed oil (LO), calcium soap of linseed oil (CaS-LO) and marine algae oil (AO). The most effective lipid supplement to increase n-3 FA in milk was AO. 22:6 n-3 and total n-3 PUFA content increased from 0.02 and 0.60% (control) to 2.63 and 3.53% (AO), respectively. All diets supplemented with n-3 FA diminished the content of saturated FA in milk and its atherogenic index, while the levels of trans-11 18:1 and cis-9 trans-11 18:2 significantly increased. Overall, the enhancement of n-3 FA in ewe’s milk would be advantageous for the manufacture of nutritionally improved cheeses.

Physicochemical composition, nitrogen fraction and volatile profiles of goat cheese made with artisanal liquid coagulant

In this study, physicochemical composition, nitrogen fractions and volatile compounds of goat cheeses manufactured using artisanal liquid coagulant by four different manufacturers in a mountainous area were investigated. Fresh goat cheeses were characterized by their high fat and high levels of total free amino acids. Volatile profiles were isolated by a solid-phase microextraction technique (SPME/GC-MS) and analyzed by gas chromography-mass spectrometry (GC-MS). In the cheeses, 50 aroma components were identified as ten acids, nine terpens, nine alcohols, eight esters, six aldehydes, five ketones, two volatile phenols and one norisoprenoid with 13 carbon atoms. The major aroma compounds found were nonanoic acid, 2-hexanol and acetoin.

Positive effects of thermosonication in Jamun fruit dairy dessert processing

The effects of thermosonication processing (TS, 90 °C, ultrasound powers of 200, 400, and 600 W) on the quality parameters of Jamun fruit dairy dessert compared to conventional heating processing (high-temperature short time, (HTST), 90 °C/20 s) were evaluated. Microbiological inactivation and stability, rheological parameters, physical properties, volatile and fatty acid profiles, and bioactive compounds were assessed. TS provided more significant microbial inactivation (1 log CFU mL-1) and higher microbial stability during storage (21 days) than HTST, with 3, 2, and 2.8 log CFU mL-1 lower counts for yeasts and molds, aerobic mesophilic bacteria, and lactic acid bacteria, respectively. In addition, TS-treated samples showed higher anti-hypertensive (>39%), antioxidant (>33%), and anti-diabetic (>27%) activities, a higher concentration of phenolic compounds (>22%), preservation of anthocyanins, and better digestibility due to the smaller fat droplet size (observed by confocal laser scanning microscopy). Furthermore, lower TS powers (200 W) improved the fatty acid (higher monounsaturated and polyunsaturated fatty acid contents, 52.78 and 132.24%) and volatile (higher number of terpenes, n = 5) profiles and decreased the atherogenic index. On the other hand, higher TS powers (600 W) maintained the rheological parameters of the control product and contributed more significantly to the functional properties of the products (antioxidant, anti-hypertensive, and anti-diabetic). In conclusion, TS proved to be efficient in treating Jamun fruit dairy dessert, opening space for new studies to define process parameters and expand TS application in other food matrices.

Near-infrared techniques for fraud detection in dairy products: A review

The dairy products sector is an important part of the food industry, and their consumption is expected to grow in the next 10 years. Therefore, the authentication of these products in a faster and precise way is required for the sake of public health. This review proposes the use of near-infrared techniques for the detection of food fraud in dairy products as they are faster, nondestructive, environmentally friendly, do not require sample preparation, and allow multiconstituent analysis. First, we have described frequent forms of food fraud in dairy products and the application of traditional techniques for their detection, highlighting gaps and counterproductive characteristics for the actual global food chain, as longer sample preparation time and use of reagents. Then, the application of near-infrared spectroscopy and hyperspectral imaging for the detection of food fraud mainly in cheese, butter, and yogurt are described. As these techniques depend on model development, the coverage of different dairy products by the literature will promote the identification of food fraud in a faster and reliable way.

Effects of Grazing Season on Physico-Chemical Characteristics and Fatty Acids of Nutritional Interest of Caciocavallo Palermitano Cheese

The aim of this work was to evaluate, in the different production seasons of the year, the physico-chemical quality of an artisanal cheese traditionally obtained from autochthonous grazing cows, with particular reference to fatty acids (FA) of nutritional interest that play an important role in the risk or prevention of some human pathologies. For this purpose, cheeses were sampled in 11 farms, repeating the samplings in 3 different periods of the year (summer, autumn-winter, and spring) when the productive conditions of the pastures varied. The cheeses produced in the spring period, when cows ingest a greater amount of grazed forage, resulted in a more adequate composition of the main FA, which are recognized as having a health effect, such as α-linolenic, trans-vaccenic, rumenic, docosapentaenoic (DPA) and docosahexaenoic (DHA) acids. Branched-chain FA were found in greater quantities in spring cheeses, as well as in summer ones. The FA composition of cheeses produced in the different seasons was reflected in some nutritional indexes that also resulted as more suitable in cheeses obtained in the spring period. The positive effects induced on the FA profile of cheeses are presumably linked to the diet of autochthonous cows, which is mainly based on forage from natural pastures. Therefore, the results obtained confirm the benefits of grazing, which is able to guarantee the production of healthier cheeses for consumers.

Preliminary Study of Extended Ripening Effects on Peptides Evolution and DPPH Radical Scavenging Activity in Mexican Goat Cheese

Cheese ripening causes intense proteolysis, particularly when the cheese contains starter cultures. Several studies have shown the presence of bioactive peptides in goat’s milk cheeses with antioxidant activity. Mexican goat cheeses’ peptide fractions were evaluated at different ripening stages. Additionally, they were correlated with their antioxidant activity. Proteolysis was measured in the acid-soluble nitrogen and non-protein nitrogen fractions using reverse-phase high-performance liquid chromatography. While the antioxidant activity in both nitrogenous fractions was determined using a 2,2-diphenyl-1-picrylhydrazyl solution. Analyzed cheeses showed peptides fraction in the retention time of 2.05, 18.36, and 50.11 min for acid-soluble fraction and non-protein protein nitrogen, and showed antioxidant activity from the first day of ripening to 73% discoloration in the DPPH solution at 55 ripening days. Obtained results suggested that ripened Mexican goat cheese had a DPPH radical scavenging activity related to peptides present originally in the milk or released by starter culture action during cheese ripening.

Can sucrose-substitutes increase the antagonistic activity against foodborne pathogens, and improve the technological and functional properties of sheep milk kefir?

The effect of different types of sugar (sucrose, demerara, brown, fructose, coconut sugar, and honey) on sheep milk kefir was evaluated. Microbial counts (Lactobacillus, Lactococcus, Leuconostoc, yeast), antagonistic activity against foodborne pathogens, microstructure (scanning electron microscopy), and antiproliferative activity of cancer cells were evaluated. Furthermore, the antioxidant activity (DPPH), inhibitory activity of angiotensin-converting enzyme (ACE), α-amylase, and α-glucosidase, lactose content, lactic and acetic acids and ethanol, fatty acid profile and volatile organic compounds were determined. The addition of sugars increased the Lactobacillus population (up to 2.24 log CFU/mL), metabolites concentration, antagonistic activity against pathogens, antioxidant activity (11.1 to 24.1%), ACE inhibitory activity (27.5 to 37.6%), α-amylase inhibition (18 to 37.4%), and anti-proliferative activity. Furthermore, it improved the fatty acid profile and volatile compounds. The results suggest that the replacement of sucrose with different types of sugar constitute an interesting option to be used in sheep milk kefir formulations.

Relationship Between the Fatty Acid Profiles and Gut Bacterial Communities of the Chinese Mitten Crab (Eriocheir sinensis) From Ecologically Different Habitats

The gut microbiota plays an important role in a variety of physiological functions such as intestinal digestion, metabolic homeostasis, immune response, and responses to disease treatment. Whether there is a relationship between gut microbial communities and fatty acid (FA) profiles of Chinese mitten crab is unclear. Hence, we analyzed the relationship between FA profiles and the gut bacterial communities of six Chinese mitten crab (Eriocheir sinensis) populations from different lakes. The crabs were sampled from six different lakes in Jiangsu Province, China. The FA profiles of these crab populations were compared and clustered, and then used to determine the relationship between geographic location and FA composition. We also characterized the gut microbial communities of these crabs using 16S rRNA high-throughput gene sequencing. The FA profiles varied significantly (P < 0.05) between crabs from different geographical locations. A similar trend was also observed in the gut microbial communities, which also varied significantly based on their geographical origin (P < 0.05). Furthermore, alpha diversity, cluster analysis, and matching bacterial community structures with specific locations revealed patterns that significantly linked FA profiles to the gut microbiota. Further analysis of FA profiles and gut microbial community generated patterns that linked the two parameters. Hence, it was observed that the gut microbial community seems to contribute significantly to the FA composition of the Chinese mitten crab. However, further studies need to be conducted to investigate the interactions between gut microbial communities and the biochemical composition of the Chinese mitten crab, which will ultimately unravel the complexity of microbial ecosystems for potential applications in aquaculture and species conservation.

The use of of inulin, maltitol and lecithin as fat replacers and plasticizers in a model reduced-fat mozzarella cheese-like product

BACKGROUND

Mono-, di- and oligosaccharides, polyhydric alcohols and lipids are three main types of plasticizers used to process food materials. In the present study, inulin, maltitol and lecithin were selected as representative oligosaccharide, polyhydric alcohol and lipid fat replacers, respectively. Their effects on the physicochemical properties of reduced-fat mozzarella cheese were evaluated.

RESULTS

Lecithin reduced the hardness and increased the degree of free oil released. Inulin and lecithin decreased the hydrophobic interaction of reduced-fat cheese. Maltitol improved the elasticity of the reduced-fat cheese and increased the hydrophobic interaction within the casein matrix. Maltitol-added cheese had a lower glass transition temperature (T_g ) than the other cheeses. Maltitol significantly improved the stretchability of the reduced-fat cheese.

CONCLUSION

The results obtained in the present study suggest that maltitol is an effective fat replacer in reduced-fat mozzarella cheese and might enhance the cheese's functional properties. The T_g of cheese was related to the water and fat content, fat replacer addition and cross-linking degree of casein. The relationship between T_g and the physicochemical properties of cheese will be studied in further research. © 2019 Society of Chemical Industry.