Dietary selenium intake in lactating dairy cows modifies fatty acid composition and volatile profile of milk and 30-day-ripened caciotta cheese

Selenium content in milk and dairy products: Estimation of the daily intake and assessment of the potential risk to public health

In this study, selenium levels in milk (n = 19), cheese (n = 49), yogurt (n = 13) and ayran (n = 8) of different brands sold in Türkiye were first determined by inductively coupled plasma mass spectrometry. The daily selenium intake resulting from the consumption of these foods was then calculated and evaluated with non-carcinogenic health risk. Selenium levels ranged from 9 - 32 and 1- 83 μg/L for milk and ayran, respectively, and from 0 - 224 and 12- 172 μg/kg for cheese and yogurt, respectively. The total daily selenium intake of persons aged 15> (general population) was determined to be 20.4 μg/day (0.292 μg/kg bw/day). The foods contributing most to the total daily selenium intake for all individuals in the same age group were yogurt (51.4 %), ayran (25.7 %), cheese (20.2 %) and milk (2.7 %). For individuals aged 15> (general population), the Target Hazard Quotient values resulting from the consumption of each food (milk, cheese, yogurt and ayran) and the Hazard Index value calculated by consuming all foods together (0.058) were less than 1. This study was detected any health risks related to selenium intake. This study was the first to evaluate health risks of selenium intake from consumption of some milk and dairy products in adult individuals.

Qualitative Attributes of Commercial Pig Meat from an Italian Native Breed: The Nero d’Abruzzo

The main objective of this study was to characterize the main qualitative properties of commercial meat obtained from the Nero d’Abruzzo pig, a native breed of Central Italy. In order to valorize this animal production, a direct comparison was made with commercial meat products obtained from hybrid pigs. Over a period of 30 days, 76 steaks for each breed were purchased from the market, and samples were analyzed for total lipid content, fatty acids profile, Coenzyme Q10 content, resistance of meat to oxidative processes, volatile profile of cooked meat and electrophoretic profile of myofibrillar and sarcoplasmic proteins. Results showed the Nero d’Abruzzo to be richer in fat, which, however, is characterized by a higher concentration of α-linolenic acid, to which are attributed important health benefits. The native breed was also richer in Coenzyme Q10, a compound credited with antioxidant potential, whose presence could explain the better oxidative stability of meat samples that were cooked and stored for up to 7 days at +4 °C. In support of this last data, our finding of the characterization of the volatile profile of cooked meat, at the end of the storage period, showed in Nero d’Abruzzo a reduction in the accumulation of hexanal, notoriously associated with oxidative events and the development of unpleasant aromatic notes. In conclusion, aspects that can justify the nutritional superiority of this niche production compared to meat coming from cosmopolitan breeds have been identified.

Can Moderate Levels of Organic Selenium in Dairy Cow Feed Naturally Enrich Dairy Products?

Simple Summary

Milk and dairy products, such as cheese and yogurt, can be useful sources of selenium-enriched products to increase human Se intake. We studied the effect of dairy cow feed supplementation with inorganic plus organic Se on milk yield, and on the Se enrichment of milk and dairy products to obtain naturally enriched products. Two groups of lactating cows were assigned to two feeding treatments, both with 0.240 mg Se/kg of ration dry matter: One was supplemented with inorganic Se, the other with a 60/40 ratio of inorganic Se/organic Se. The results showed that the inclusion of inorganic plus organic Se did not affect the yield or basic chemical composition of milk; however, the Se content of milk was higher with inorganic plus organic Se supplementation. Cheese from cows fed inorganic plus organic Se had a higher Se content, although this effect was not observed for yogurt. At a moderate level in the diet, sodium selenite plus Se yeast may be more effective than only inorganic Se, increasing the Se concentration in milk and cheese.

Abstract

This work studied the effect of dairy cow ration supplementation with inorganic plus organic Se on metabolic status, milk yield, and the quality of milk and dairy products, especially its Se content. Twenty multiparous Holstein Friesian lactating cows were assigned to two feeding treatments. The cows were fed with 22.5 kg dry matter (DM) of total mixed ration (11.75 kg DM of forage plus 10.75 kg DM of concentrate) by head. There were two different concentrates with the same Se content (0.240 mg/kg of ration DM) but with different Se sources: The control (CON) was supplemented with inorganic Se (sodium selenite); and the other (IOSe) was supplemented with sodium selenite plus organic Se (Sel-Plex^®), at 0.144 and 0.096 mg Se/kg of ration DM, respectively. The results indicated that, in general, the IOSe treatment did not modify the metabolic profile, and even decreased the total oxidant status (p < 0.05) and did not lead to a deterioration of quality and yield of milk. However, milk and cheese from IOSe had higher Se content (an increase of 29.7% and 38.2%, respectively) than CON (p < 0.01), but this effect was not observed in yogurt. In general, physical or sensorial parameters of cheeses did not show differences between treatments. Moderate inorganic plus organic Se supplementation may be more effective than inorganic Se, increasing the Se content in milk and cheese, without causing a deterioration in quality or productive parameters.

Physical, Nutritional, and Sensory Properties of Cheese Obtained from Goats Fed a Dietary Supplementation with Olive Leaves

Simple Summary

This study aims to investigate the effects of cheese obtained from goats fed a dietary supplementation with olive leaves. Thirty Saanen goats were allocated into two groups, (1) a control group that received a standard diet, and (2) an experimental group whose diet was supplemented with olive leaves. The results suggest a positive role of olive leaves in improving the cheese fatty acids composition and oxidative stability during ripening. Moreover, there were several variations in the development of volatile flavor compounds, even if no changes were evidenced in the sensory properties.

Abstract

The aim of this study is to evaluate the physical, nutritional, and sensory properties of cheese obtained from goats fed a dietary supplementation with olive leaves (OL). Thirty Saanen goats were randomly allocated into two groups of 15 goats each, (1) a control group fed with a standard diet (CG), and (2) an experimental group (EG) fed an OL-enriched diet. The trial lasted for 30 days. The milk of each group was then collected and used to produce Caciotta cheese, which was analyzed at the beginning and at the end of the ripening period (60 days). The results showed a positive effect of dietary OL supplementation in improving the fatty acid profiles due to the significant increase of unsaturated fatty acids, mostly α-linolenic acid (C18:3 n-3), with the consequent reduction of the ω-6/ω-3 ratio, a condition commonly associated with an increased health functionality of food products. Moreover, improved oxidative stability was observed in cheese during ripening, a presumable consequence of the transfer into the milk of dietary bioactive compounds, mainly polyphenols of high biological value, and credited as a marked antioxidant potential. Furthermore, reduced lipolytic action was observed in 60-day ripened cheese, even if no significant changes in sensory properties were evidenced.

Volatile Profile in Yogurt Obtained from Saanen Goats Fed with Olive Leaves

The aim of this study was to evaluate the development of volatile compounds in yogurt samples obtained from goats fed a dietary supplementation with olive leaves (OL). For this purpose, thirty Saanen goats were divided into two homogeneous groups of 15 goats each: a control group that received a standard diet (CG) and an experimental group whose diet was supplemented with olive leaves (OLG). The trial lasted 28 days, at the end of which the milk of each group was collected and used for yogurt production. Immediately after production, and after 7 days of storage at 4 °C in the absence of light, the yogurt samples were characterized in terms of fatty acid profile, oxidative stability and volatile compounds by the solid-phase microextraction (SPME)-GC/MS technique. Dietary OL supplementation positively affected the fatty acid composition, inducing a significant increase in the relative proportion of unsaturated fatty acids, mainly oleic acid (C18:1 cis9) and linolenic acid (C18:3). With regard to the volatile profile, both in fresh and yogurt samples stored for 7 days, the OL supplementation induced an increase in free fatty acids, probably due to an increase in lipolysis carried out by microbial and endogenous milk enzymes. Specifically, the largest variations were found for C6, C7, C8 and C10 free fatty acids. In the same samples, a significant decrease in aldehydes, mainly heptanal and nonanal, was also detected, supporting-at least in part-an improvement in the oxidative stability. Moreover, alcohols, esters and ketones appeared lower in OLG samples, while no significant variations were observed for lactones. These findings suggest the positive role of dietary OL supplementation in the production of goats' milk yogurt, with characteristics potentially indicative of an improvement in nutritional properties and flavor.

Proteolytic Volatile Profile and Electrophoretic Analysis of Casein Composition in Milk and Cheese Derived from Mironutrient-Fed Cows

The aim of the study was to evaluate the proteolytic process in Caciocavallo cheese obtained from Friesian cows fed zinc, selenium, and iodine supplementation. Thirty-six Friesian cows, balanced for parity, milk production, and days in milk, were randomly assigned to four groups. The control group (CG) was fed with a conventional feeding strategy, while the three remaining groups received a diet enriched with three different trace elements, respectively zinc (ZG), selenium (SG), and iodine (IG). At the end of the experimental period, samples of milk were collected and used to produce Caciocavallo cheese from each experimental group. Cheese samples were then analyzed after 7 and 120 days from the cheese making in order to obtain information on chemical composition and extent of the proteolytic process, evaluated through the electrophoretic analysis of caseins and the determination of volatiles profile. Both milk and cheese samples were richer in the amount of the microelement respectively used for the integration of the cattle’s diet. The zymographic approach was helpful in evaluating, in milk, the proteolytic function performed by endogenous metalloenzymes specifically able to degrade gelatin and casein; this evaluation did not highlight significant differences among the analyzed samples. In cheese, the electrophoretic analysis in reducing and denaturing condition showed the marked ability of β-casein to resist the proteolytic action during ripening, whereas the dietary selenium supplementation was shown to perform a protective action against the degradation of S1 and S2 isoforms of α-casein. The analysis of the volatile profile evidenced the presence of compounds associated with proteolysis of phenylalanine and leucine. This approach showed that selenium was able to negatively influence the biochemical processes that lead to the formation of 3-methyl butanol, although the identification of the specific mechanism needs further investigation.

Dietary Grape Pomace Supplementation in Dairy Cows: Effect on Nutritional Quality of Milk and Its Derived Dairy Products

Grape pomace (GP) is the main solid by-product of winemaking and represents a rich source of potent bioactive compounds which could display a wide range of beneficial effects in human health for their association with reduced risk of several chronic diseases. Several studies have proposed the use of GP as a macro-ingredient to obtain economically worthwhile animal feedstuffs naturally enriched by polyphenols and dietary fibers. Moreover, the research carried out in this field in the last two decades evidences the ability of GP to induce beneficial effects in cow milk and its derived dairy products. First of all, a general increase in concentration of polyunsaturated fatty acids (PUFA) was observed, and this could be considered the reflection of the high content of these compounds in the by-product. Furthermore, an improvement in the oxidative stability of dairy products was observed, presumably as a direct consequence of the high content of bioactive compounds in GP that are credited with high and well-characterized antioxidant functions. Last but not least, particularly in ripened cheeses, volatile compounds (VOCs) were identified, arising both from lipolytic and proteolytic processes and commonly associated with pleasant aromatic notes. In conclusion, the GP introduction in the diet of lactating cows made it possible to obtain dairy products characterized by improved nutritional properties and high health functionality. Furthermore, the presumable improvement of organoleptic properties seems to be effective in contributing to an increase in the consumer acceptability of the novel products. This review aims to evaluate the effect of the dietary GP supplementation on the quality of milk and dairy products deriving from lactating dairy cows.

Volatile Flavor Compounds in Cheese as Affected by Ruminant Diet

Extensive research has been conducted concerning the determination and characterization of volatile compounds contributing to aroma and flavor in cheese. Considerable knowledge has been accumulated on the understanding of the mechanisms through which these compounds are formed during ripening, as well as on the optimization of the methodological approaches which lead to their detection. More recently, particular attention has been given to the aromatic properties of milk and cheeses obtained from lactating dairy ruminants fed experimental diets, characterized, for instance, by the addition of trace elements, natural supplements, or agricultural by-products rich in bioactive compounds. The purpose of this review is to summarize the major families of volatile compounds most commonly found in these types of dairy products at various ripening stages, describing in greater detail the role of animal diet in influencing the synthesis mechanisms most commonly responsible for cheese flavor determination. A large number of volatile compounds, including carboxylic acids, lactones, ketones, alcohols, and aldehydes, can be detected in cheese. The relative percentage of each compound depends on the biochemical processes that occur during ripening, and these are mainly mediated by endogenous enzymes and factors of bacterial origin whose function can be strongly influenced by the bioactive compounds taken by animals with the diet and released in milk through the mammary gland. Further evaluations on the interactions between volatile compounds and cheese matrix would be necessary in order to improve the knowledge on the synthesis mechanisms of such compounds; in addition to this, more should be done with respect to the determination of synergistic effects of flavor compounds, correlating such compounds to the aroma of dairy products.

Influence of Licorice Root Feeding on Chemical-Nutritional Quality of Cow Milk and Stracciata Cheese, an Italian Traditional Fresh Dairy Product

Simple Summary

The aim of this study was to investigate the effects of dietary licorice root supplementation on chemical and nutritional characteristics of cow milk and Stracciata cheese, an Italian traditional fresh dairy product. Our results suggest a positive role of licorice in improving the nutritional and organoleptic properties of dairy cow products, influencing various parameters such as fatty acid and volatile profiles.

Abstract

The aim of this study was to evaluate the effect of dietary licorice root supplementation on chemical and nutritional characteristics of cow milk and Stracciata cheese. Licorice did not influence milk and Stracciata fat content but induced modifications in fatty acid profile. Both in milk and Stracciata, a decrease in saturated fatty acids was detected and in cheeses an increase of monounsaturated and polyunsaturated fatty acids was observed. Stracciata obtained from the experimental group showed an improved oxidative stability after six days of ripening, a finding partly justifiable by the well-known richness of antioxidant compounds in the licorice root. The volatile profile of Stracciata was also affected by dietary licorice intake, with an increase in esters and a reduction of aldehydes and ketones. These results suggest a positive role of licorice in modifying chemical and physical properties of cow cheeses, reducing lipid oxidation and inducing changes in color and flavor with a presumable improvement in consumer acceptability.