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ObjectiveTo analyze the quality changes of Platycladi Semen before and after the deterioration of moth-eaten and rancidity during storage. MethodFour types samples of Platycladi Semen， including normal， moth-eaten， oxidative rancidity and hydrolytic rancidity， were determined for volatile components， odor， and taste based on headspace solid phase microextraction/gas chromatography-mass spectrometry （HS-SPME/GC-MS） and electronic sensory techniques such as electronic nose and electronic tongue. Volatile components were identified by searching the database and manual comparison， the odor and taste were determined by the response values of the electronic nose and electronic tongue sensors， and the difference between samples before and after deterioration was studied by multivariate statistical analysis. ResultA total of 85 compounds were identified in Platycladi Semen samples. Compared with the normal samples， the number of volatile compounds in samples after hydrolytic rancidity decreased by 5， the number of volatile compounds in samples after moth-eaten and oxidative rancidity increased by 1 and 21， respectively. Aldehydes and acids accounted for majority of types. Among them， the contents of N-hexanoic acid， hexanal and propionic acid in the samples of oxidative rancidity reached 11.49%， 10.21% and 7.52%， which became the key indicators of rancidity. There was significant variance among the odor components corresponding to W1W， W2W and W1S sensors by electronic nose analysis. It was indicated that the value of sourness in deteriorated samples generally increased by mean of electronic tongue analysis. Compared with normal samples， the moth-eaten samples had changed slightly and rancidity samples had changed significantly especially oxidative rancidity samples of volatile components， odor and taste by multivariate statistical analysis. ConclusionIn terms of Platycladi Semen， the oxidative rancidity caused by nature storage for 12 months has the greatest impact on the quality. Therefore， it should be mainly to prevent oxidative rancidity to ensure the quality of Platycladi Semen.
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Objective:To explore the mechanism of rancidity during storage by researching the changes of water content， relative permeability of cell membrane and rancidity levels of Armeniacae Semen Amarum in deterioration process. Method:Armeniacae Semen Amarum samples under different storage conditions were evaluated and classified by sensory assessors， and samples with different levels of rancidity were obtained. Water content was measured by toluene method， and water activity was obtained by water activity meter. Malondialdehyde （MDA） and relative conductivity were measured using thiobarbituric acid colorimetry and conductivity meter， respectively. The content of fatty oil was obtained by Soxhlet extraction. The acid value and peroxide value were measured in accordance with the general rules 0713 and 2303 of the 2020 edition of <italic>Chinese Pharmacopoeia</italic> （part Ⅳ）， respectively. Based on the above experimental data， chemometric methods （cluster analysis， principal component analysis） were selected to establish classification and discriminant models of Armeniacae Semen Amarum with different rancidity levels， in order to verify the accuracy of the classification results. Result:According to the results of sensory evaluation， Armeniacae Semen Amarum samples were divided into three classes， including no rancidity， slight rancidity and rancidity. Compared with the no rancid samples， the color of surface and cotyledon were deepened in rancid samples， and the oil was appeared on surface with rancid taste. The values of water content， water activity， MDA content and relative conductivity were all significantly increased in deterioration process （<italic>P</italic><0.01）. The content of fatty oil was significantly decreased with the occurrence of rancidness （<italic>P</italic><0.01）， while the acid value and peroxide value increased significantly （<italic>P</italic><0.01）. The results of cluster analysis and principal component analysis showed that the rancid samples could be distinguished from the no rancid and slightly rancid samples. Conclusion:The storage conditions under high temperature and high humidity can accelerate the rancidness of Armeniacae Semen Amarum， which is accompanied by the increase of internal water content， the increase of cell membrane permeability and the occurrence of fatty acid rancidity. It is suggested that Armeniacae Semen Amarum should be stored in low temperature， dry environment， as well as short storage time.
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El uso de microondas está muy extendido a nivel doméstico gracias a su rapidez y facilidad de uso. El objetivo del presente trabajo es comparar el efecto de cocción de hamburguesas de distintos tipos de carne, en microondas y en horno convencional, sobre la pérdida de peso y estabilidad oxidativa. Además, determinar si existen diferencias desde el punto de vista sensorial aplicando una prueba triangular, comparando 2 productos presentados en tríos, uno que corresponde a hamburguesa cocida en microondas y otro a hamburguesa cocida en horno convencional. Se adquirieron hamburguesas de pollo, pavo, cerdo y vacuno en el comercio, se cocinaron en horno convencional y en microondas. Se calculó pérdida por cocción, se evaluó la rancidez y diferencias sensoriales entre hamburguesas del mismo tipo de carne, cocidas en distinto tipo de horno. La pérdida por cocción fue menor en hamburguesas cocidas en microondas. La acidez e índice de peróxido aumentaron en las muestras cocidas en ambos tipos de hornos respecto a hamburguesas crudas. La acidez fue mayor en hamburguesas cocidas en horno convencional, y el índice de peróxido fue mayor en hamburguesas cocidas en microondas, llegando a 10,6 meq O2/kg. En el análisis sensorial se encontraron diferencias significativas (p<0,05) entre las hamburguesas cocidas en horno convencional y en microondas. Resulta mejor opción cocinar hamburguesas en horno convencional, ya que el índice de peróxidos es menor que al cocinar en microondas; dentro del tipo de hamburguesas, son más estables las de vacuno y cerdo frente a la oxidación.
The use of microwaves is very widespread at the domestic level thanks to its speed and ease of use. The aim of this study was to compare cooking loss, rancidity and sensory differences for hamburger patties cooked in conventional versus microwave ovens. We also determined sensorial differences with the triangular test, comparing two products presented in threesomes, one that corresponded to a patty cooked in the microwave and the other in a conventional oven. Chicken, turkey, pork and beef patties were purchased commercially, cooked in a conventional oven and in microwaves. Cooking loss was calculated, rancidity and sensory differences were evaluated between patties of the same type of meat and cooked in the different oven types. Cooking loss was lower in patties cooked in microwaves compared to those cooked in conventional ovens. For both oven types, acidity and peroxide index increased with respect to raw ones. Acidity was higher in hamburgers cooked in conventional ovens and the peroxide index was higher in burgers cooked in microwaves, reaching 10.6 meq O2/kg. In sensory analysis, significant differences were found (p<0.05) between patties cooked in a conventional oven and in microwaves. It is a better option to cook patties in a conventional oven, because the peroxide index is smaller than in microwaves; and within types of patties, beef and pork are more stable against oxidation.
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Fornos , Culinária/métodos , Produtos da Carne/análise , Micro-Ondas , Peróxidos/análise , Paladar , AcidezRESUMO
Abstract The aim of this study was to evaluate the physical and chemical changes in cashew nut flour under different packaging and storage conditions. The flour samples were characterized according to their chemical composition, packaged in polystyrene trays associated with covering chloride polyvinyl (PVC), plastic pot of polyethylene terephthalate (PET), plastic packaging polyethylene (POL) and without coating polystyrene trays (CON). All packages were stored for 225 days, evaluating every 45 days the moisture content of the flour as well as extracting their oil by the cold method for characterization on the following indexes: acidity, saponification, iodine, peroxide and refraction. There was slight and gradual increase in the moisture content from the 45th to the 225th day, especially for products packaged in PVC and without coating polystyrene trays (CON). The oil saponification indexes showed gradual decrease during storage, especially in flour without packaging (CON). There was a gradual increase in the iodine index until the 135th day, followed by decay. The acidity and peroxide indexes increased along with the storage time. However packages with lower oxygen and moisture permeability, such as PET and POL, minimized such changes, being therefore the most suitable for long-term storage.
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O objetivo deste estudo foi avaliar o perfil de ácidos graxos (AG), os índices de qualidade nutricional e a estabilidade oxidativa (EO) de manteigas produzidas do leite de vacas alimentadas com dietas à base de cana-de-açúcar contendo níveis crescentes de óleo de girassol (OG): 0 (controle); 1,5; 3,0 e 4,5% da matéria seca (MS). O perfil de AG das manteigas foi analisado por cromatografia gasosa, e a EO foi determinada utilizando-se o equipamento Rancimat®, modelo 743, operado a 120ºC e fluxo de ar de 20L/h. As concentrações dos AG rumênico (CLA cis-9, trans-11), vacênico (C18:1 trans-11) e oleico (C18:1 cis-9) na gordura das manteigas foram aumentadas em 867, 687 e 148%, respectivamente, à medida que se aumentou de 0 para 4,5% o nível de OG na dieta. Por outro lado, as concentrações dos AG saturados de cadeia média foram linearmente reduzidas (P<0,0001) na gordura das manteigas, em razão do incremento de OG nas dietas. Quanto aos índices de qualidade nutricional, houve redução linear (P<0,0001) no índice de aterogenicidade e no de trombogenicidade e aumento da relação entre AG hipo e hipercolesterolêmicos, em resposta ao aumento do nível de OG na dieta. Consistente com o incremento (P<0,0001) nas concentrações totais dos AG mono e poli-insaturados, a EO da gordura das manteigas foi linearmente reduzida (P<0,0001) em razão do incremento de OG nas dietas. Concluiu-se que a suplementação com OG melhorou a qualidade nutricional das manteigas produzidas do leite de vacas Holandês x Gir devido a mudanças positivas no perfil de AG da gordura. Entretanto, tais mudanças na composição dos AG da gordura foram acompanhadas de redução da EO das manteigas, associada à menor vida de prateleira.
The objective of this study was to evaluate the fatty acid (FA) profile, nutritional quality and oxidative stability (OE) indexes of butter obtained from milk of cows fed sugar cane-based diets containing increasing levels of sunflower oil (SO): 0 (Control); 1.5; 3.0 and 4.5% of diet DM. The butter FA profile was analyzed by gas chromatography and OE was determined using the Rancimat® equipment (model 743) operated at 120ºC and air flow of 20 L/h. The concentrations of rumenic acid (cis-9 trans-11 CLA), vaccenic acid (trans-11 C18:1) and oleic acid (cis-9 C18:1) in butter fat were increased by 867, 687 and 148%, respectively, as the dietary SO level increased from 0 to 4.5%. In contrast, the concentrations of medium chain saturated FA were linearly reduced (P<0.05) in butter fat from cows fed increasing levels of SO. Regarding the butter nutritional quality, a linear decrease (P<0.0001) in atherogenicity and thrombogenicity indexes and a linear increase (P<0.0001) in the hypocholesterolemic/ hypercholesterolemic ratio were observed compared to control, 1.5, 3.0 and 4.5% SO, respectively. Consistent with the increased (P<0.0001) concentration of mono and polyunsaturated FA, the OE of butter fat was linearly reduced (P<0.0001) as the dietary SO level increased. It was concluded that diet supplementation with SO improved the nutritional quality of butter fat of Holstein x Gir dairy cows as a result of positive changes in milk FA profile. However, these changes in milk FA composition were accompanied by a reduction in the SO of butter, which in turn is associated with a shorter shelf life.
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Animais , Feminino , Bovinos , Fenômenos Fisiológicos da Nutrição Animal , Laticínios/análise , Leite , Avaliação NutricionalRESUMO
A oxidação lipídica é uma das principais alterações que acometem os derivados cárneos em razão da composição química rica em lipídios e íons ferro, utilização de processos térmicos e de moagem, além do frequente uso do cloreto de sódio, um reconhecido catalisador desta reação. Os antioxidantes são substâncias utilizadas para inibir ou retardar a rancidez oxidativa, porém, seu uso desperta a atenção de consumidores e agências reguladoras, quanto à segurança que acompanha o consumo de aditivos sintéticos. Este trabalho teve por objetivo avaliar o uso dos carotenoides bixina e norbixina como antioxidantes em produtos cárneos por meio da revisão de suas características químicas, métodos de obtenção, toxicidade e aplicações tecnológicas. Esses pigmentos são extraídos das sementes do urucum (Bixa orellana L.) por métodos que envolvem o uso de solventes orgânicos, extração supercrítica ou ainda a utilização da tecnologia de micro-ondas. No Brasil, o uso dessas substâncias é previsto na legislação como corante alimentício, porém, estes carotenoides apresentam extensas cadeias carbônicas insaturadas que permitem a adição de radicais livres e lhes conferem a capacidade de atuar como antioxidantes. As diferenças estruturais entre bixina e norbixina resultam em particularidades quanto à polaridade, solubilidade, coloração e, por consequência, determinam singulares aplicações tecnológicas. Nas concentrações previstas pelas agências reguladoras, o consumo desses carotenoides é seguro e além das aplicações como corante, podem ser utilizados pela indústria como antioxidantes naturais, oportunizando uma alternativa capaz de substituir ou minimizar o uso de aditivos sintéticos em produtos cárneos.
Lipid oxidation is one of the major modifications that affect meat products due to chemical composition, heat and grinding processes beyond the routine use of sodium chloride, a recognized catalyst of this reaction. Antioxidants are substances used to inhibit or retard oxidative rancidity. However the use of these compounds has been drawing the attention of consumers and regulatory agencies about the safety of synthetic additives consumption. This study aimed to evaluate the use of carotenoids bixin and norbixin as antioxidants in meat products by review of the chemical characteristics, methods of production, toxicity and technological applications. These pigments are extracted from annatto (Bixa orellana L.) using organic solvents, supercritical extraction or microwaves. In Brazil, the use of these substances is forecast by law as food colorant, however, this carotenoids show a large unsaturated carbon chains that allow the addition of free radicals and enable their use as antioxidant. The structural differences between bixin and norbixin result in distinct polarity, solubility and coloration, and consequently in different technological applications. At concentrations established by regulatory agencies, the use of these compounds is safe and, in addition to applications such as dyes, can be used by industries as natural antioxidants, which is an alternative capable of replace or minimize the use of synthetic additives in meat products.
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The aim of this work was to study the effect of gamma radiation on lipids by TBARS and NMR. The samples of raw whole milk were subjected to gamma radiation from Co60 in doses of 1, 2 and 3 kGy and the production of rancidity was studied through Nuclear Magnetic Resonance (NMR) and Thiobarbituric Acid Test (2-TBARS). The TBARS values increased according to the intensity of the radiation dose applied at the samples, demonstrating correlation between the radiation dose and the production of lipid oxidation. This was confirmed by NMR with the formation of peaks of aldehydes and ketones that were small and similar in the doses of 1 and 2 kGy. In the dose of 3 kGy, the total degradation of milk fat was observed. A correlation between the NMR and 2-TBA was detected.
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Acompanhou-se o desenvolvimento dos processos da salga em salmoura saturada (salga úmida) e salga seca de filés de tilápia-do-nilo (Oreochromis niloticus) e avaliaram-se algumas características indicativas de qualidade do produto durante a estocagem. Os processos foram acompanhados por 156 horas na salga úmida e por 96 horas na salga seca, e os filés salgados foram estocados, respectivamente, por 60 e 45 dias à temperatura ambiente. Os teores máximos de cloreto nos filés (14 por cento) foram atingidos com 72 horas na salga úmida e com 36 horas na salga seca. Os filés de tilápia salgados em salmoura mantiveram as características próprias do produto por um período de 45 dias, e os submetidos à salga seca apresentaram baixo teor de umidade (6 por cento) e alta concentração de extrato etéreo (4,6 por cento). Recomenda-se somente o processo de salga em salmoura saturada como forma de conservação dos filés de tilápia-do-nilo.
The processes of salting of Nile tilapia fillets (Oreochromis niloticus) submitted to saturated brine and dry salting were observed, and some characteristics that indicate the quality of the product during the storage were evaluated. The brine saturated process was followed up to 156 hours and the dry salting was followed up to 96 hours. When the salting finished, fillets were stored for 45 (dry salting) and 60 days (saturated brine), respectively. The highest values for chloride in fillets (14 percent) were reached within 72 hours in brine salting and 36 hours in dry salting. The tilapia fillets salted in brine kept the proper characteristics of the product for a period of 45 days and the fillets submitted to dry salting showed low moisture ratios (6 percent) and a high concentration of lipids (4.6 percent). Thereby, it is only recommended the salting process in saturated brine to be used as a mean of conservation for Nile tilapia fillets.
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Animais , Ciclídeos , Cloretos , Conservação de Alimentos/métodos , Contaminação de Alimentos/análise , Qualidade dos AlimentosRESUMO
Parte del producto de la pesca se devuelve al mar aunque pudiera comercializarse. Tal es el caso del pez volador (Dactylopterus volitans), debido a que su morfología dificulta su manipulación. Este estudio tuvo por objetivo evaluar el efecto del tiempo sobre las características bacterianas y físico-químicas en filetes del pez volador almacenados a -18°C durante 6; 39; 67 y 95 días. Se realizaron recuentos (UFC/g) de aerobios mesófilos a 25 y 32°C y de Staphylococcus aureus y determinación del NMP/g de coliformes fecales y Escherichia coli. También se determinó humedad, pH y el índice de rancidez. El tiempo de almacenamiento bajo congelación no ejerció ningún efecto en los recuentos bacterianos, pues no se halló evidencia significativa (P > 0,05) de multiplicación o disminución de los mismos. Los recuentos de aerobios mesófilos en placa fueron bajos, no hubo crecimiento de S. aureus y el valor más alto de coliformes fecales fue de 240 NMP/g. Sin embargo, los valores de rancidez oxidativa y de pH si fueron significativamente diferentes (P < 0,05) durante el lapso de almacenamiento. El índice del ácido tiobarbitúrico varió de 0,27 hasta 3,12 mg de malonaldehído/kg debido, probablemente a la interacción de diversos factores, entre ellos, a los fragmentos de piel que quedaron en los filetes, presencia de sustancias pro-oxidantes y a las fluctuaciones de temperatura durante el almacenamiento. A pesar del incremento de la rancidez, la apariencia y el olor no indicaron deterioro. Se concluye que esta especie pudiera comercializarse bajo la modalidad de filetes siempre y cuando a los filetes se les elimine completamente la piel, se glaseen, se empaquen herméticamente y se vigilen las temperaturas de almacenamiento.
A part of the fish captured is discarded despite the fact that it could be commercialized. This is the case of flying gurnards´s fish (Dactylopterus volitans) because its morphology difficults its handling, even though it is eaten in differents forms. The objective of this research was to determine the effect of time on the bacteriological, physical and chemical characteristics of gurnard fillets kept in storage at -18°C during 6; 39; 67 and 95 days. Mesophilic aerobic plate counts (CFU/g) were made at 25 and 32°C and S. aureus. Also the most probable number (MPN/g) of fecal coliforms and E. coli was determined. Humidity was likewise determined, together with pH and the rancidity index. There was not evidence that the frozen storage´s days are a significant factor (P > 0.05) in the bacterial counts. Bacteriological results confirmed that during the processing steps hygienic and temperature norms were followed, since the aerobic plate counts were low, S. aureus did not grow and the highest number of fecal coliforms was 240 MPN/g. On the other hand, the frozen storage´s time influences significantly (P < 0.05) the lipid oxidation´s rate in frozen fillets because the thiobarbituric acid index oscillated from 0.27 to 3.12 mg malonaldehyde/kg, probably due to some skin fragments in the fillets, substances with pro-oxidative propierties and for temperature fluctuations in the storage. Nevertheless, in despite of rancidity increase, the appearance and the odor did not show signs of spoiling. In conclusion, this species could be commercialized in the form of fillets provided that the freezing, defrosting and storage temperatures are watched at all times. It is highly recommended that the fillets are fully peeled, glazed and packed air tight.