Pier Giorgio Peiretti

Determination of carnosine, anserine, homocarnosine, pentosidine and thiobarbituric acid reactive substances contents in meat from different animal species

The aim of this research was to determine the content of the histidinic antioxidants, advanced glycation end products (pentosidine) and thiobarbituric acid reactive substance (TBARS) in the meat from different animal species. Carnosine, anserine, homocarnosine and pentosidine were quantified by HPLC/MS, while TBARS was determined by photometric measurements. The total CRCs (carnosine+anserine+homocarnosine) content was in the increasing order: beef<rabbit<pork<horse<chicken<turkey. The analysis showed traces of pentosidine above the instrumental determination limits in all the meat samples, while the susceptibility of these meat to lipid oxidation decreased from beef to chicken, with the exception of turkey meat, which presented a high TBARS content towards even though its total CRCs was the highest. The structure of homocarnosine was elucidated by high resolving power multistage mass spectrometry.

Effect of cooking method on carnosine and its homologues, pentosidine and thiobarbituric acid-reactive substance contents in beef and turkey meat.

Commercial samples of beef and turkey meat were prepared by commonly used cooking methods with standard cooking times: (1) broiled at 200°C for 10min, (2) broiled at a medium temperature (140°C) for 10min, (3) cooked by microwave (MW) for 3min and then grilled (MW/grill) for 7min, (4) cooked in a domestic microwave oven for 10min, and (5) boiled in water for 10min. The raw and cooked meats were then analysed to determine the carnosine, anserine, homocarnosine, pentosidine, and thiobarbituric acid-reactive substance (TBARS) contents. It was observed that boiling beef caused a loss of approximately 50% of the carnosine, probably because of the high water solubility of carnosine and its homologues; cooking by microwave caused a medium loss of the anti-oxidants of approximately 20%; cooking by MW/grill led to a reduction in carnosine of approximately 10%. As far as the anserine and homocarnosine contents were concerned, a greater loss was observed for the boiling method (approximately 70%) while, for the other cooking methods, the value ranged from 30% to 70%. The data oscillate more for the turkey meat: the minimum carnosine decrease was observed in the cases of MW/grill and broiling at high temperature (25%). Analogously, the anserine and homocarnosine contents decreased slightly in the case of MW/grill and broiling at a high temperature (2-7%) and by 10-30% in the other cases. No analysed meat sample showed any traces of pentosidine above the instrumental determination limits. The cooked beef showed an increased TBARS value compared to the raw meat, and the highest values were found when the beef was broiled at a high temperature, cooked by microwave or boiled in water. The TBARS value of the turkey meat decreased for all the cooking methods in comparison to the TBARS value of the fresh meat.

Effects of Chia (Salvia hispanica L.) seed supplementation on rabbit meat quality, oxidative stability and sensory traits

Chia (Salvia hispanica L.) seed (SHS) dietary supplementation is effective in improving the nutritional quality of rabbit meat for consumers and could contribute to the novel concept of “functional food” in human nutrition. A trial has been conducted in order to verify the effects of three levels (0, 10, or 15%) of SHS inclusion in a rabbit diet on the meat quality, oxidative stability and sensory traits. The dietary treatment did not induce any differences in the ultimate pH, chemical composition, drip losses of the longissimus dorsi muscle or the initial and ultimate pH of the biceps femoris muscle, but the SHS supplementation increased cooking losses of the rabbit meat. The inclusion of SHS also reduced oxidative stability during meat storage. No adverse effects were observed on the meat quality or customer acceptability. The inclusion of SHS in rabbit diets, which is effective in improving the n-3 polyunsaturated fatty acids content of meat, increased the lipid oxidation in the hind leg meat. An improvement in tissue oxidative stability could be obtained by feeding rabbits with higher levels of antioxidants.

Effects of Dietary Fatty Acids on Lipid Traits in the Muscle and Perirenal Fat of Growing Rabbits Fed Mixed Diets.

Simple Summary Polyunsaturated fatty acids in human foods have been shown to have health benefits. We investigated the potential to incorporate them into rabbit meat by adding them to the diet. Good relationships between dietary fatty acids (FAs) and their content in longissimus dorsi muscle and perirenal fat of rabbits was established, especially the latter. The results should make it possible to enhance the polyunsaturated fatty acid content of rabbit meat, with benefits to the health of human consumers. Abstract The aim of this study was to evaluate the effects of various raw materials (spirulina, curcuma, tomato pomace, false flax, linseed, chia, perilla seeds) as suitable polyunsaturated fatty acid n-3 (n-3 PUFA) sources, on the lipid traits in the longissimus dorsi muscle and perirenal fat of growing rabbits. The fatty acid (FA) analyses of the diets, carried out by gas chromatography, differed over a wide range on the basis of the highly varied ingredients in 27 experimental formulations. Among the 29 identified FAs, three from feeds were catabolized in the rabbits, five were de novo synthesized and stored chiefly in the muscle. It was possible to linearly characterize the incorporation from the feed to the muscle of 16 FAs. This study has confirmed that the dietary inclusion of various raw materials could be considered as a way of enriching the n-3 PUFA of rabbit meat. A proposal for the prediction of n-3 PUFA from dietary α-linolenic acid (C18:3 n-3) and a panel of another 10 FAs has been made for intramuscular fat (R2 = 0.94) and perirenal fat (R2 = 0.96).

Appraisal of ingestion and digestibility in growing rabbits using near infrared reflectance spectroscopy (NIRS) of feeds and faeces

Abstract The aim of this work was to examine whether faecal profiling using NIRS could be profitable for promote the Best Available Techniques (BAT) in the rational feeding of rabbits. A set of 51 feed samples, taken from 12 experimental diets, and of 66 dried grouped faeces samples, belonging to four nutrition experiments, with 130 ad libitum registered feed intakes (CV=25%), were submitted to a UV-Vis-NIRS scan (350-2500 nm) in order to calibrate the chemical composition and nutritional parameters, the ingestion aptitude and digestibility. A chemometric system has made it possible to contemporary use the spectrum of the input diet concatenated together with the spectra of the related output pool of the dried faeces. The daily measured feed intake, in absolute or in relative terms as ingestion per unit of metabolic weight, obtained a good resolution for the spectra of the feeds (R2cv=0.80 and 0.75, respectively), for the faeces (0.81 and 0.80) and for the joint evaluation of the concatenated spectra (0.87 and 0.81). The intake was positively correlated to the mineral, insoluble ash, protein, gross energy, crude fiber and acid detergent fiber (ADF) content in the feeds, and negatively correlated to the N-free extract, lignocellulose and all the digestibility coefficients, except crude fiber. Very significant improvements, on average equal to 0.20 R2 points, were also provided to the digestibility coefficients when using the concatenated method; in decreasing order: neutral detergent fiber (R2cv=0.00, 0.18 and 0.50 for the feeds, faeces and concatenated, respectively), ADF (0.00, 0.45 and 0.62), ether extract (0.53, 0.52 and 0.86), crude protein (0.53; 0.53 and 0.75), and gross energy (0.61; 0.74 and 0.83). The results corroborate previous knowledge and show the possibility of using NIRS faecal profiling in rabbit nutrition, which together with the NIRS of the feeds, could contribute to nitrogen monitoring.

Effects of Rosemary Oil (Rosmarinus officinalis) on the Shelf-Life of Minced Rainbow Trout (Oncorhynchus mykiss) during Refrigerated Storage

The effects of three concentrations (0.2%, 1% and 3%) of rosemary oil (RO) on the freshness indicators, oxidative stability, fatty acid and biogenic amine (BA) contents of minced rainbow trout muscle (MTM) were investigated after different periods of storage (three and nine days) at 4 ± 1 °C. Moreover, the terpene and sesquiterpene contents in the treated MTM were also measured. RO treatment improves the pH, oxidative stability of the lipids and the FA profile, which resulted in a significant extension of MTM shelf-life. Storage time influenced all freshness indicators, with the exception of yellowness and chroma. Treatment with RO had a positive effect, leading to low BA content, especially putrescine, cadaverine, tyramine and histamine. Differences in BA were also found to be due to storage time, with the exception of spermidine, which was not influenced by time. Moreover, the presence of the terpenoid fraction of RO in MTM improved the quality of this ready-to-cook fish food.

Fresh meat quality of pigs fed diets with different fatty acid profiles and supplemented with red wine solids

Three groups of pigs were fed three different diets, namely a diet rich in saturated fatty acids (palm oil-based, PO), a polyunsaturated fatty acid (PUFA)-rich diet (corn oil-based, CO), and a PUFA-rich diet (corn oil-based) supplemented with red wine solids (RWS), which was added to the diet (CO+RWS) in order to assess the protective effect on the oxidative status of the pork meat. The addition of corn oil favourably modulates the FAs profile of the backfat, and to a lesser extent of the intramuscular fat of semimembranosus muscle, without causing adverse effects on the meat quality or on its oxidative stability. Moreover, these parameters were not affected by the addition of the RWS in the CO+RWS diet.

Effects of diets with increasing levels of golden flaxseed on carcass characteristics, meat quality and lipid traits of growing rabbits

The aim of this study was to determine the effects of three levels (0, 8, or 16%) of the golden variety of flaxseed (GFS; Linum usitatissimum L.), included in isonitrogenous and isocaloric diets, on the carcass characteristics, meat composition and fatty acid profile of rabbit meat and perirenal fat. The trial was carried out on 30 weaned crossbred rabbits aged 9 weeks, weighing on average 2074 g. The animals were divided equally into three groups of 10 (five male and five female rabbits each) and kept separate in individual cages. At the end of the experiment, which lasted 5 weeks, there were no significant differences between the groups in the carcass yield or the proportions of various carcass parts and edible organs. Although the chemical composition of the meat was not significantly affected by the dietary treatment, the saturated fatty acid and monounsaturated fatty acid proportion in the longissimus dorsi muscle (−22% and −24%, respectively) and perirenal fat (−34% and −29%, respectively) decreased and the polyunsaturated fatty acid (PUFA) increased (+36% in the muscle and 43% in the fat, respectively) with increased GFS inclusion. GFS dietary supplementation has shown to be effective in improving the n-3 PUFA proportion (76% in the muscle and 77% in the fat, respectively), decreasing the n-6/n-3 ratio and reducing the saturation, atherogenic and thrombogenic indexes of the meat, with consequent benefits on the nutritional quality of rabbit meat for consumers.

Apparent digestibility of mixed feed with increasing levels of perilla (Perilla frutescens L.) seeds in rabbit diets

The aim of this study was to determine the effects of three levels (0, 5 and 10%) of perilla (Perilla frutescens L.) seeds (PFS), included in isonitrogenous and isocaloric diets, on the apparent digestibility in rabbit aged of 73 days. The trial was carried out on 30 crossbred (Carmagnola Grey x New Zealand) rabbits randomly divided in three groups of ten animals each (five male and five female rabbits). Each of them was kept in individual cages. The faeces were collected during the last week of a growing trial that lasted 50 days. No obvious health problems were encountered during the experiment and no rabbits died during the trial. The measured parameters were digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fibre, acid detergent fibre and gross energy. The only parameter that was modified by the inclusion of PFS was the ether extract digestibility; it resulted higher in the 10% PFS diet (83.9%) than in the other two diets. Perilla seed may be used satisfactorily as a nutrient supplement for rabbits at levels of up to 10% in the diet with a better digestibility of ether extract than in the other two diets.

Antioxidative activities and phenolic compounds of pumpkin (Cucurbita pepo) seeds and amaranth (Amaranthus caudatus) grain extracts

Abstract Phenolic compounds were extracted from pumpkin (Cucurbita pepo) seed and amaranth (Amaranthus caudatus) grain into 80% (v/v) methanol. The extracts obtained were characterised by the contents of total phenolic compounds (TPC), trolox equivalent antioxidant capacity (TEAC), ferric-reducing antioxidant power (FRAP) and antiradical activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical. The content of individual phenolic compounds was determined by HPLC-DAD method. Pumpkin seeds showed the higher content of TPC than that from amaranth. The TEAC values of both extracts were similar each other. The lower value of FRAP was observed for pumpkin seed. Phenolic compound present in amaranth grain exhibited strongest antiradical properties against DPPH radical. Several peaks were present on the HPLC chromatograms of two extracts. The UV-DAD spectra confirmed the presence of vanillic acid derivatives in the amaranth grain. The three main phenolic compound present in pumpkin seed were characterised by UV-DAD spectra with maximum at 258, 266 and 278 nm.