Organic chicken product authentication: state-of-the-art and future perspectives

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/63704Organic food products are highly susceptible to fraud. Currently, administrative controls are conducted to detect fraud, but having an analytical tool able to verify the organic identity of food would be very supportive. The state-of-the-art in food authentication relies on fingerprinting approaches that find characteristic analytical patterns to unequivocally identify authentic products. While wide research on authentication has been conducted for other commodities, the authentication of organic chicken products is still in its infancy. Challenges include finding fingerprints to discriminate organic from conventional products, and recruiting sample sets that cover natural variability. Future research might be oriented towards developing new authentication models for organic feed, eggs and chicken meat, keeping models updated and implementing them into regulations. Meanwhile, these models might be very supportive to the administrative controls directing inspections towards suspicious fraudulent samples

Fatty acid digestibility in gilthead sea bream fed diets containing native, re-esterified or acid vegetable oils.

Re-esterified vegetable oils are obtained from a chemical esterification reaction between vegetable acid oils and glycerol. Due to their properties, it is expected that they have a higher nutritive value than their corresponding acid oils and a better digestibility than their native counterparts. The aim of the present study was to determine the effect of reesterified oils with a different monoacylglycerol (MAG) and diacylglycerol (DAG) content, produced from palm or rapeseed, on fatty acid digestibility in gilthead sea bream (Sparus aurata). Triplicate groups of fish were fed nine experimental diets containing different oils during 28 days. For each source, four different types of oil were used: native, re-esterified low or high in MAG and DAG and acid. A commercial fish oil was used for the control diet. Diets containing re-esterified oils had better apparent digestibility coefficients (ADC) of total fatty acids than acid oil diets. Reesterified oils do not negatively affect apparent digestibility coefficients of fatty acids when compared to their corresponding native oils and could be incorporated as a source of energy in diets for gilthead sea bream. An improvement in digestibility compared to the native oil diet was only obtained in palm re-esterified oil high in MAG and DAG

Acid and re-esterified rapeseed oils as alternative vegetable oils rainbow trout diets: Effects on lipid digestibility and growth

The present study aimed at evaluating the effects of dietary acid and re-esterified rapeseed oils as alternatives to native vegetable oils (VO) on growth performance and feed utilization in rainbow trout. Acid oils are a free fatty acid (FFA)-rich by-product from the refining of VO and re-esterified oils are the final product of a chemical esterification process between acid oils and glycerol. Because re-esterified oils have a high content of mono- and diacylglycerols (MAG and DAG), known for being good emulsifiers, a higher nutritive value than that of the native and the acid oils might be expected. A 72-day feeding trial where triplicate groups of rainbow trout were fed eight experimental diets formulated to contain 15% of a native, a re-esterified and an acid rapeseed oil, in addition to a 5% of fish oil (FO), was carried out. Diets with the native or the re-esterified oils blended with the acid oil were also studied. A commercial fish oil was used for the control diet. Fish fed rapeseed acid and re-esterified oil diets (RA and RE, respectively) showed high fat and total fatty acid apparent digestibility coefficients (ADC) (RA: 90.5 ± 0.3%, RE: 92.5 ± 1.0% for total fat and RA: 95.7 ± 0.1%, RE: 95.8 ± 0.2% for total fatty acids). However, the lowest total fatty acid ADC was that obtained in animals fed RA, which was significantly lower (P b 0.05) than that of fish fed the rapeseed native oil diet (RN: 96.7 ± 0.1%). No significant differences in final weight were obtained between fish fed RA (375.9 ± 2.9 g) and RE (381.5 ± 11.1 g) and those fed RN (393.7 ± 6.1 g), even though both values were significantly lower (P b 0.05) than that of fish fed the control diet (411.1 ± 3.3 g). Nonetheless, fish fed diets including blends of the rapeseed acid and the re-esterified oils (RE/RA and RA/RE) had higher final weights (392.8 ± 4.4 and 394.6 ± 1.6, respectively) than those of RA and RE, although differences were not statistically significant. Furthermore, RA and RE diets did not produce relevant changes in plasma parameters or in the morphology of liver and intestine of fish. Therefore, the inclusion of rapeseed acid and re-esterified oils along with a 5% of FO in aqua feeds does not seem to have negative effects on fat and fatty acid digestibility, growth, plasma parameter or morphology of liver and intestine in rainbow trout. However, before recommending their use, further studies regarding their effects on the final composition and quality of fillets should be carried out. Statement of relevance: Re-esterified and acid rapeseed oils could be included in diets for rainbow trout as economically advantageous sources with no negative results in fat and fatty acid digestibility, plasma parameters and morphology of liver and intestine

Quality characteristics of fillets of rainbow trout fed acid or re-esterified rapeseed oils as dietary fat sources

Alternatives to the use of native vegetable oils (VO) as fish oil (FO) replacers in aqua feeds were evaluated. Acid oils are a free fatty acid (FFA)-rich by-product mainly from the refining of VO. Re-esterified oils are the final product of a chemical esterification reaction between acid oils and glycerol, and have less FFA and more monoand diacylglycerols (MAG and DAG), known for being good emulsifiers, than crude VO. Therefore, they could have a higher nutritive value than that of the native and acid oils. In two earlier studies in rainbow trout (Trullàs et al., 2015, 2016), diets including acid and/or re-esterified VO resulted in total fatty acid apparent digestibility coefficients above 95%. Moreover, no negative effects on growth, plasma biochemical parameters and morphology of tissues were observed when compared to the native oil diet. For all these reasons, the present study aimed at assessing their effects on the final quality of fillets of rainbow trout. Triplicate groups of rainbow trout were fed eight experimental diets containing 15% of different types of experimental rapeseed oils in addition to 5% of FO during 72 days. The experimental rapeseed oils were native (RNO), acid (RAO), re-esterified (REO), or blends (66% RN-33% RAO/33% RN-66% RAO or 66% REO-33% RAO/33% REO-66% RAO). Commercial FO was used for the control diet (F). The colorimetric analysis resulted in significant differences only in b* and C* in both fresh and thawed fillets, as well as in significant correlations between the colorimetric parameters among diets. For the total fat content, fillets of fish fed the control diet obtained the highest values, which were higher than those of fish fed diets containing RNO and the blend 66% REO-33% RAO. No differences in texture, liquid holding capacity, and TBARS were found among fillets of fish fed the different diets. Regarding tocopherol concentrations in fillets, α-tocopherol was significantly higher (P < 0.05) in fillets of fish fed the control diet than in those fed RA/RE, while β + γ-tocopherol was significantly lower in fillets of fish fed C than in the rest. Even though the aforementioned differences were found, they did not seem to be relevant concerning the final quality of fille

The different molecular structure and glycerol-to-fatty acid ratio of palm oils affect their nutritive value in broiler chicken diets

The aim of this study is to assess how the fat molecular structure and its glycerol-to-fatty acid ratio (G : FA) affect the fatty acid (FA) apparent absorption of palm oils in broiler chickens. The experimental diets were the result of a basal diet supplemented with 6% of different palm oils. Native palm oil (N), rich in triacylglycerols, was the positive control (T1), and acid palm oil (A), rich in free FA, was the negative control (T2). In order to improve the nutritive value of A, two different nutritional strategies were performed. The first strategy was achieved by adding increasing amounts of free glycerol (G) (4% (T3), 8% (T4) and 16% (T5)) to A, and the second one by adding increasing amounts of mono- (MAG) and diacylglycerols (DAG), coming from re-esterified palm oil (E) (40% (T6), 70% (T7), and 100% (T8)) to A. As a result, eight dietary treatments were formulated with a G : FA ratio ranging from 0.04 to 0.67. These treatments were randomly assigned to 192 one-day-old female broiler chickens (Ross 308), distributed in 48 cages. The results showed how, by keeping the G : FA ratio constant (0.33 mol/mol), the diet with a high MAG and DAG content (T7) achieved higher saturated FA apparent absorption values than did the diet with a high triacylglycerol content (T1) and this, in turn, more than did the diet with a high free FA content (T4). The behavior of oils with high or low G : FA ratio was dependent on whether G was in a free state or esterified as part of acylglycerol molecules. Thus, increasing amounts of G to A did not enhance the total FA apparent absorption, but rather quite the opposite, even impairing the absorption of mono- and polyunsaturated FA. However, increasing amounts of E (rich in MAG and DAG) to A (rich in FFA) did enhance total FA apparent absorption, primarily due to the increased absorption of saturated FA. In conclusion, the greater the G : FA ratio of a palm oil, the greater the absorption of total FA, as long as G is esterified as part of acylglycerol molecules. Thus, the re-esterification process for obtaining E makes sense in order to give added value to A, achieving even greater digestibility values than does its corresponding N

Oxidized oils and dietary zinc and alpha-tocopheryl acetate supplementation: effects on rabbit plasma, liver and meat fatty acid composition and meat Zn, Cu, Fe and Se content

The effects of the addition of heated oils to feeds (3%, w/w) and the dietary supplementation with a-tocopheryl acetate (TA; 100 mg/kg) and Zn (200 mg/kg) on rabbit tissue fatty acid (FA) composition and on the Zn, Cu, Fe and Se content in meat were assessed. Heating unrefined sunflower oil (SO) at 558C for 245 h increased its content in primary oxidation products and reduced its a-tocopherol content. However, this did not significantly affect tissue FA composition. Heating SO at 1408C for 31 h increased its content in secondary oxidation products and in some FA isomers asc9,t11-CLA and di-trans CLA. This led to increases in di-trans CLA in liver and in t9,c12-18:2 in meat. The c9,t11-CLA was the most incorporated CLA isomer in tissues. The dietary supplementation with a-TA did not affect the FA composition of plasma, liver or meat. The cooking of vacuum-packed rabbit meat at 788C for 5 min reduced significantly but slightly its polyunsaturated FA content. The dietary supplementation with Zn did not modify the content of Zn, Fe or Se in meat, but it reduced its Cu content. On the other hand, it increased the content of some FAs in meat when SO heated at 1408C for 31 h was added to feeds

Aquest estiu, gaudeix d’una bona orxata de xufla

L’orxata és un producte nutritiu, refrescant i molt saludable que s’obté de la xufla, un tubercle que va ser introduït pels àrabs al segle VIII. És la beguda mediterrània per excel·lència, energètica, que no conté alcohol, ni cafeïna, ni lactosa, ni fructosa i té un baix contingut en sodi, de manera que resulta una beguda ideal per prendre tota la família, tant petits com grans, sobretot en substitució de begudes carbonatades i edulcorades

Evolution of lipid classes and fatty acid digestibility along the gastrointestinal tract of broiler chickens fed different fat sources at different ages

The aim of the present study is to evaluate the effect of the dietary fat saturation degree and age on the lipid class (TAG, DAG, MAG, and FFA) composition and fatty acid digestibility along the gastrointestinal tract (GIT) and excreta in broiler chickens. A total of 120 one-day-old female broiler chickens were randomly distributed in 2 dietary treatments (6 cages/treatment), which resulted from the supplementation of a basal diet with 6% of soybean oil or palm oil. Two digestibility balances were carried out at 14 and 35 d and fatty acid digestibility and lipid class composition were determined in the gizzard, duodenum, jejunum, ileum, and excreta. Along de GIT, both fatty acid digestibility and lipid class composition were influenced by the dietary fat source and the age of the chickens. The absorption of the unsaturated fat was more efficient and faster than it was for the saturated fat. The ability of adult chickens to absorb fat was higher than for young chickens. The results show that the duodenum is the main place of fat digestion (hydrolysis), and the jejunum the main place of fat absorption. The role of the ileum on fat absorption is very important, as it is the last segment of the GIT where the absorption of fatty acids has been described. Thus, it was the contribution of the ileum that was responsible for the higher fat utilization observed for animals fed the unsaturated diet than for those fed the saturated diet at 14 d, and it was also responsible for the improvement on the utilization of the saturated diet between 14 and 35 d. All the results suggest that the absorption of fatty acids is more limiting than is hydrolysis, because the main differences were observed in the jejunum and ileum, where the absorption of fatty acids takes place

Soybean Oil Replacement by Palm Fatty Acid Distillate in Broiler Chicken Diets: Fat Digestibility and Lipid-Class Content along the Intestinal Tract

Palm fatty acid distillate (PFAD) is a by-product of palm oil (P) refining. Its use in chicken diets is a way to reduce the cost of feed and the environmental impact. Its low unsaturated:saturated fatty acid ratio (UFA:SFA) and its high free fatty acid (FFA) level could be partially counteracted by its blending with soybean oil (S). The objective was to assess the effect of replacing S with different levels of PFAD on lipid-class content and fatty acid (FA) digestibility along the intestinal tract and in the excreta of 11 and 35-day-old broiler chickens. Five experimental diets were prepared by supplementing a basal diet with S (S6), PFAD (PA6), two blends of them (S4-PA2 and S2-PA4), or P (P6) at 6%. Replacing S with PFAD did not affect performance parameters (p > 0.05) but negatively affected feed AME, FA digestibility, and FFA intestinal content (p < 0.05), especially in starter chicks. Including PFAD delayed total FA (TFA) absorption (p < 0.05) at 11 days, but at 35 days it did not affect the TFA absorption rate. The use of PFAD blended with S, when FFA ≤ 30% and UFA:SFA ≥ 2.6, led to adequate energy utilization in broiler grower-finisher diet

Optimization of analytical methods for the assessment of the quality of fats and oils used in continuous deep fat frying

La aplicabilidad, repetibilidad y capacidad de diferentes métodos de análisis para discriminar muestras de aceites con diferentes grados de oxidación fueron evaluadas mediante aceites recogidos en procesos de fritura en continuo en varias empresas españolas. El objetivo de este trabajo fue encontrar métodos complementarios a la determinación del índice de acidez para el control de calidad rutinario de los aceites de fritura empleados en estas empresas. La optimización de la determinación de la constante dieléctrica conllevó una clara mejora de la variabilidad. No obstante, excepto en el caso del índice del ATB, el resto de métodos ensayados mostraron una menor variabilidad. La determinación del índice del ATB fue descartada ya que su sensibilidad fue insuficiente para discriminar entre aceites con diferente grado de oxidación. Los diferentes parámetros de alteración determinados en los aceites de fritura mostraron correlaciones significativas entre el índice de acidez y varios parámetros de oxidación diferentes, como la constante dieléctrica, el índice de p-anisidina, la absorción al ultravioleta y el contenido en polímeros de los triacilgliceroles. El índice de acidez solo evalúa la alteración hidrolítica, por lo que estos parámetros aportan información complementaria al evaluar la alteración termooxidativa