159 research outputs found
Feeding influence on the oxidative stability of poultry meat treated with ozone
No full textOzone is considered a strong antimicrobial agent with numerous potential applications in alimentary industry. However, its high oxidizing potential can induce alterations in foods by acting in particular on the unsaturated fatty acids. The aim of this study was to investigate the effect of ozonation on the oxidative stability of chicken breast meat obtained from animals subjected to different feeding strategies
INFLUENCE OF DEHYDRATED MEDICAGO SATIVA ON QUALITY CHARACTERISTICS OF MARCHIGIANA BEEF
No full textThe composition of cattle diets is one the most important parameters influencing meat quality .Effects of pasture alone and supplementation with dehaydrated Medicago sativa on carcass and meat quality were studied in Marchigiana beef cattle, in particular lipid and stability. Meat quality measurements were made on Longissimus dorsi (LD) muscle in 20 animals slaughtered at 660-700 kg. The amount of lipids in the control group was lower with higher percentage of polyunsaturated fatty acids (PUFA), especially linoleic (C18:2) and linolenic (C18:3) acid. There were significant differences (P≤0.01) of TBARS values that were higher in the group fed with supplementation of Medicago sativa than in the other group, the control one
Evaluation of Chemical-Nutritional Characteristics of Whey and Ricotta Obtained by Ewes Fed Red Grape Pomace Dietary Supplementation
No full textThis study aimed to investigate the effect on the chemical quality of whey and Ricotta obtained from ewes fed a red grape pomace (GP) dietary supplementation. The analyses were performed on whey, before and post Ricotta cheese-making, and in Ricotta after 1 (T1) and 5 (T5) d of ripening at 4°C. Moreover, fatty acid profile of whey before ricotta (WBR) cheese-making and Ricotta T1 of ripening and volatile profile of Ricotta T1 and T5 were investigated. The diet did not affect whey and Ricotta lipid content, conversely, significant variations were instead observed with regard to color. A lower amount of total phenolic compounds was found in WBR cheese-making, on the contrary, an opposite trend was highlighted in Ricotta T1 although no variations in antioxidant properties were detected. Moreover, GP modified fatty acid profile of whey and Ricotta but did not have any effect on protein profile of the main whey protein. The reduction of hexanal in Ricotta during the ripening suggest a better oxidative stability. The obtained results therefore suggested that the GP inclusion in the ewes diet, while modifying some chemical parameters, did not induce negative effects on the characteristics and quality of dairy by-products
Volatile Flavor Compounds in Cheese as Affected by Ruminant Diet
No full textExtensive 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
BIOGENIC AMINES CONTENT OF POULTRY BREAST STORED UNDER DIFFERENT CONDITIONS AT + 4°C FROM TWO DIFFERENT INDUSTRIAL GENOTYPE CHICKENS
No full textIn this experimental work, forty breast chickens of two different industrial genotype, were analysed at 4, 8, 11 and 15 days from slaughtering. All breast chickens were divided in two groups. A group was stored at 4°C, and the other was stored at 4°C in sterilised water added with antibiotic (400 mg/l Enrofloxacin). BAs quantitative determination was carried out by means of HPLC, with spectrophotometric-UV detection. The amines were extracted in HClO4 and derivatised by dansylchloride. In the samples stored in sterile water added with antibiotic, no bacterial growth was observed until the end of the experimental period. Significant differences in BAs accumulation were observed between the two samples groups, while BAs content was different during time. In fact, in samples stored in sterilised water added with the antibiotic, the presence of some BAs, such as spermine and spermidine, was revealed, probably due to the action of tissue enzymes
Effect of dried liquorice root supplementation on chemical-nutritional quality of dairy products obtained from goats
No full textEnriching 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
No full texthis 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
Effect of whey supplementation on the fatty acids composition of chicken eggs
No full textOne trial with two groups of hens carried out to investigate the influence of whey supplementation on egg yolk quality. For the experiment group was used a solution of water 10% and 90% while for the control group was used only water (100%). Eggs from each treatment were analyzed after four weeks of feeding and were collected daily and stored at 4 °C. Eggs were boiled in water at 100 °C for 10 Min.The whey supplementation carried out egg yolks with different aromatic profile and similar fatty acid composition compared to sample coming from the control group. The color and the lipid content are not different between the two groups even if in the experimental group color was always higher then the control, probably due to an antioxidant effect of some compound present in the whey. [...
Influence of Oral Supplementation with Whey on Egg Quality Characteristics and Fatty Acid Composition
No full textThe effects of whey supplementation on egg quality characteristics and fatty acid composition were studied. A total of 240 ISA hens were used and divided into two uniform groups: for the experiment group was used a solution of water 10% and whey 90% while for the control group was used pure water (100 %). Eggs were collected daily after 30 days of feeding and stored at 4 °C during the experiment. Lastly eggs were boiled in water at 100 °C for 10 minutes and then be analyzed (0 days). The advance of the oxidative state was also assessed at 6 days after cooking. The whey supplementation carried out egg yolks with different % of some volatile compounds and similar lipids and fatty acid composition compared to samples coming from the control group. The colour and lipid oxidative stability of egg yolk are significantly different between the two groups. MDA value was lower in the experimental group, while the colour was higher than the control, probably due to an antioxidant effect of some compounds present in the whey. Supplementation of whey in the diet of laying hens has positive effects on the quality of eggs, especially on oxidative stability
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