Qualitative and quantitative phytochemical analysis of different extracts from Thymus algeriensis aerial parts

This study was performed to evaluate the metabolite recovery from different extraction methods applied to Thymus algeriensis aerial parts. A high-performance liquid chromatographic method using photodiode array detector with gradient elution has been developed and validated for the simultaneous estimation of different phenolic compounds in the extracts and in their corresponding purified fractions. The experimental results show that microwave-assisted aqueous extraction for 15 min at 100 C gave the most phenolics-enriched extract, reducing extraction time without degradation effects on bioactives. Sixteen compounds were identified in this extract, 11 phenolic compounds and five flavonoids, all known for their biological activities. Color analysis and determination of chlorophylls and carotenoids implemented the knowledge of the chemical profile of this plant

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

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

Dietary supplementation of Saanen goats with dried licorice root modifies chemical and textural properties of dairy products.

ABSTRACT The aim of the present study was to evaluate the effect of dietary integration with dried licorice root on the chemical-nutritional qualities of goat milk and cheeses. The study was conducted for 60 d, during which 30 Saanen goats were divided into 2 groups: a control group (CG) that received a standard diet and an experimental group (LG+) whose diet was supplemented with licorice. At the end of the study, milk samples were collected to determine chemical-nutritional compositions and fatty acid (FA) profiles. Cheeses produced with CG and LG+ bulk milk were analyzed for chemical-physical parameters after 3 (T3) and 30 (T30) d of ripening. A different FA profile and a significant increase in protein and casein were observed in LG+ milk samples compared with CG milk. Regarding cheeses, an increase of proteins and fat was found in LG+ cheeses, which also were harder, more elastic, and more gummy than the CG samples after both 3 and 30 d of ripening. A different protein profile was detected in the 2 groups without significant variations in casein fractions (αS2-casein and β-casein) during ripening. Moreover, greater oxidative stability was found in LG+ cheeses at both T3 and T30. Different families of volatile compounds were detected in T30 cheeses obtained from both groups. A significant reduction of octanoic acid and an increase in nonanal and ketones were found in LG+ T3 cheeses, whereas the LG+ T30 cheeses were characterized by a significant decrease of hexanoic acid an increase of 3-methyl-1-butanol and acetoin. We concluded that it is possible to assert that dietary integration with dried licorice root modified chemical and technological properties of goat cheeses, reducing lipid oxidation during ripening and inducing changes in texture that could improve consumer acceptability, although further studies are needed from this point of view

Evaluation of the chemical-nutritional parameters and the aromatic profile of eggs obtained from laying hens fed with a dietary supplementation of extruded linseed

Hen eggs represent a traditional food with an excellent nutritive value due to the presence of highly digestible proteins, vitamins, minerals and lipids, such as polyunsaturated fatty acids (PUFAs). Lipid composition of hen eggs is a subject of primary consumer concern, due to the relationship between specific dietary lipids and the development of coronary heart diseases (CHD). Nowadays, it is well known that ω-3 PUFAs provide important health benefits to humans as prevention and treatment of many ANIMAL PRODUCTS chronic diseases. The most significant ω-3 PUFAs appear to be α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and doco- sahexaenoic acid (DHA) and for the mentioned reasons over the course of time a growing interest has been developed in the pro- duction of eggs rich in ω-3 fatty acids, by feeding laying hens with experimental feedstuffs containing these nutrients. For example, ALA is predominantly in seed oils such as flax (Linum usitatissimum). Linseed is unique among oilseeds because of their exceptionally high content of ALA (≅50% of the total oilseed). The aim of this work was to determine the effect of the hens diet integration with extruded flaxseed (7%) on productive parame- ters and on the quality of resultant Bio-ω-3 eggs. At the end of the treatment, no significant difference was observed for eggs production while it was observed for the aver- age egg weight (58.05 ± 1.94% for control eggs vs. 63.37 ± 2.14% for flax eggs). Regarding, instead, the chemical-nutritional parameters, significant differences were not observed for total lipids and in the TBARs-test while significant differences were observed in the acidic profile. Specifically, ω-3 PUFAs were higher in flax eggs (p< .01) while SFA were higher in control eggs (p<.01). Also, β-carotene was found higher in flax eggs (478.20±15.19 μg/g vs. 324.80±13.84 μg/g, p<.001). The aro- matic profile was, also, analysed and significant differences were observed both for the alcohols and aldehydes compounds (p< .05). Finally, a significant difference in the colour was observed between the two types of eggs (ΔEab=1.77 ± 0.23, p<.05). In conclusion, it is possible to assert that the integration of the laying hens diet gave positive results as it has not negatively affected the production parameters, has improved the ω-6/ω–3 ratio (5.9:1 for flax eggs vs. 62:1 for control eggs) and the β-car- otene content, and has decreased the percentage of SFA guilty of cardiovascular pathologies

Effect of dried liquorice root supplementation on chemical-nutritional quality of dairy products obtained from goats

Enriching the goat’s diet with plant extracts, rich in bioactive compounds, allow to improve the chemical-nutritional properties of dairy products. Liquorice has anti-inflammatory, antimicrobial, antioxidative effects associated with the presence of compounds, as triterpene saponins, flavonoids and coumarins The aim of the present work was to evaluate the effect of dietary integration with 8% of dried liquorice root on chemical-nutri- tional quality of goat milk and cheeses. The study was conducted for 60 days on Saanen goats divided into two groups: a control group (CG) and an experimental group (LG+) whose diet was supplemented with liquorice. Milk samples were collected to determinate chemical-nutritional composition and fatty acids profile (FA) at 30 and 60 days from the beginning of the study. At the end of the experiment, cheeses produced with CG and LG + bulk milk were analysed for chemical–physical parameters at 3 (T3) and 60 (T60) days of ripening. A different FA profile and a significant increase in proteins (p<.01) and casein (p<.01) percentage but no variation in lipids, lactose, urea and in FA were observed in LG+milk samples respect to CG milk. Regarding cheeses, no variation in lipid and protein but a lower water content (p<.05) were found in LG + T3 and T60 cheeses, this reflected in a different texture. Indeed, the LG+cheeses were harder, more elastic and more gummy than the CG cheeses and these differences were observed both in fresh and aged cheeses. Moreover, the LG + cheeses showed a yellowish colour probably correlated to the presence in LG + milk of specific compounds of liquorice roots, such as tannins, carotenoids and ascorbic acid which have antioxidant activity and are also respon- sible for the yellow colour. A greater presence of antioxidant compounds deriving from liquorice roots can be also correlated with greater oxidative stability found in both LG + T3 (p<.05) and T30 (p<.05) cheeses. Different families of volatile compounds were detected in T30 cheeses obtained from the two groups. A significant reduction of octanoic acid (p<.05) and a significant increase in nonanal (p<.01) were found in LG+T3 cheeses, instead in LG + T60 cheeses, significant increases of 3-methyl, 1-butanol (p<.01) and acetoin (p<.05) have been found. In conclusion, it is possible to assert that the integration with liquorice has modified chemical and technological properties of goat cheeses, improving the oxidative stability and inducing changes in texture and colour

Dietary selenium supplementation of Friesian cows modifies the aromatic profile of dairy products

his study aimed to investigate the effect of dietary selenium (Se) supplementation of Friesian cows on the aromatic properties of dairy products. Thirty-two Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The trial lasted 63 days in which the control group (CG) was fed with a conventional feeding strategy, while the experi- mental group (SeG) received daily selenomethionine (SeMet) supplementation. During the experimental period, the milk yield was monitored and samples of milk and related Caciocavallo cheese were collected and analysed in order to obtain information on chemical-nutritional composition. To evaluate the effect of ripening on the aromatic profile, the analysis was performed on cheese samples collected after 7 (T7) and 120 (T120) days after the cheese-making. The volatile compounds composition resulted positively affected by dietary Se intake, with a significant increase in concentration of carboxylic acids, esters and lactones (p<.05), reflecting the predominance of the lipolytic processes respect to the proteolytic events. The general increase of carboxylic acids in ripened cheese could be explained by the extent of starter cell autolysis, with the consequent release of peptidases and espe- cially lipases that accelerate the lipolytic events. Among the most represented carboxylic acids must be indicated butanoic and ANIMAL PRODUCTS hexanoic acids; such compounds are considered to be mainly involved in the determination of cheese flavour, giving origin to cheesy, rancid and sweaty odours. The increased production of such compounds could be probably explained by an increase of lipolysis of the triglycerides by microbial and endogenous milk enzymes, resulting in an augmented release of free fatty acids (FFAs). With regard to the esters, such compounds are charac- terised by a low odour threshold and are generally associated with the sweet, fruity, and floral notes of surface-ripened cheese fla- vour. Lactones, instead, are generally produced by a one-step transesterification reaction of hydroxylated FFAs which represent the main precursors. Such findings could contribute to the pro- duction of cheeses with interesting organoleptic properties, although further sensorial evaluations should be performed to deeply investigate these changes and confirm the consumer acceptability

Zinc supplementation of lactating dairy cows: effects on chemical-nutritional quality and volatile profile of Caciocavallo cheese

Objective The aim of the present study was to investigate the effect of dietary zinc supplementation of Friesian cows on chemical-nutritional and aromatic properties of Caciocavallo cheese after 7 days (C7) and 120 days (C120) of ripening. Methods Twenty eight Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional complete diet, while the experimental group (ZG) received a daily zinc supplementation of 60 mg for kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciocavallo cheese were collected and analyzed for chemical-nutritional composition and aromatic profile. Results The enrichment of dairy cows diet with zinc, did not influence milk yield and composition, however a marked reduction of somatic cell count (SSC) was evidenced. Both in milk and cheese the ZG samples were characterized by a lower concentration of satured fatty acids (SFA) and an increase in oleic, vaccenic and rumenic acids. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, esters and lactones. Conclusion The present results suggest a positive role of dietary zinc intake in improving the quality of bovine milk and related cheese, in particular for the increase in concentration of bioactive fatty acids such as rumenic acid. The changes evidenced in cheese through the analysis of the volatile profile, would be consistent with the development of interesting organoleptic properties, although further evaluations should be performed to confirm the consumer acceptability of these changes

Effects of selenium supplementation on chemical composition and aromatic profiles of cow milk and its derived cheese

This study aimed to investigate the effect of dietary selenium supplementation of Friesian cows on chemical- nutritional and volatile fraction of caciocavallo cheese. A sample of 32 Friesian cows, balanced for parity, milk production, and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional feeding strategy, while the experimental group (SeG) received a daily selenomethionine supple- mentation of 0.45 mg/kg in total mixed ration. During the experimental period, milk yield was monitored, and samples of milk and caciocavallo cheese were collected and analyzed to obtain information on chemical-nutri- tional composition and volatile compounds profile. Di- etary Se integration did not induce variations on milk yield or composition but markedly lowered the somat- ic cell count (SCC). In both milk and cheese, samples from SeG were characterized by a lower concentration of saturated fatty acids (SFA) and increases in linoleic and rumenic acids. The volatile compounds profile of dairy products was also positively affected by dietary Se intake, with an increase in concentration of free fatty acids, esters, and aldehydes. These results suggest that Se plays a positive role in improving bovine mammary gland functionality and the nutraceutical properties of milk and caciocavallo cheese made therefrom. Such findings could contribute to the production of cheeses with interesting organoleptic properties, although further sensorial evaluations should be performed to deeply investigate these changes and confirm consumer acceptability

High temperature and heating effect on the oxidative stability of dietary cholesterol in different real food systems arising from eggs

Cholesterol, a monounsaturated sterol present in food of animal origin, can be oxidized during food processing and storage, thus generating a series of oxidation products, collectively called oxysterols. These compounds are increasingly considered of potential interest in the onset and development of vascular disease due to their ability to trigger irreversible damage of vascular cells with consequent activation of phagocytes, up-regulation of the expression and synthesis of adhesion molecules and inflammatory cytokines. The understanding of the conditions, in the presence of which the cholesterol oxidation occurs in foods, could certainly help to prevent the accumulation of oxysterols, allowing to avoid harmful effects on human health. The aim of this work was to verify the presence of 7-ketocholesterol, the most representative of oxysterols family, in eggs and derivative obtained through different procedures of cooking. In the light of our results, we confirmed that the temperature and the lipid nature of the food matrix are closely related to the oxidative stability of cholesterol in foodstuffs. In particular, we tested 7-ketocholesterol formation in the presence of palm oil, rich in saturated fatty acids, or soybean oil, rich in polyunsaturated compounds

Zinc supplementation of Friesian cows: Effect on chemical-nutritional composition and aromatic profile of dairy products

nc represents an essential microelement for several biochemical mechanisms. The body's inability to store zinc necessarily requires a constant dietary supply to avoid alteration of physiological functions. The aim of the present study was to investigate the effect of dietary enrichment with zinc on chemical-nutritional and aromatic properties of milk and cheese. Thirty commercial dairy cows, balanced for parity, milk production, and days in milk, were randomly assigned to 2 groups. The control group was fed with a conventional complete diet (22 kg of dry matter/animal per day), whereas the experimental group received a daily zinc supplementation of 60 mg per kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciotta cheese were collected to obtain information about the chemical-nutritional composition and aromatic profile. Dietary zinc integration did not influence milk yield and composition, but induced a marked reduction of somatic cell count and improved the oxidative stability of ripened caciotta cheese. In both milk and cheese, the experimental group samples were characterized by a lower concentration of saturated fatty acids and an increase in oleic acid, vaccenic acid, and rumenic acid. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, aldehydes, and esters. The present results suggest a positive role of zinc in improving animal health and nutraceutical properties of milk and corresponding cheese. Taking into account the analysis of volatile compounds, zinc dietary supplementation of dairy cows should contribute to the production of cheeses with interesting organoleptic properties, although more studies are necessary to confirm the consumer acceptability of these changes