Rancid Flavor Research Articles

A Comparative Study on Yayık Butter Produced with Commercial and Endemic Yogurt Starter Culture Strains

This study evaluates the effect of using four different starter culture combinations in yogurt samples used in Yayık butter production. Two of the combinations were isolated strains (27 St/27 Lb) and (27 St/A Lb) used in Yayık butter samples of A and B. The other two were commercial cultures (CHI) and (Y080 F) used for samples C and D, respectively. The Yayık butter samples were analyzed in serum pH, titratable acidity, fat, acid degree value, peroxide value, free fatty acids, volatile compounds, and sensory properties in the 1st, 30th, and 60th days of storage. The serum pH differed significantly among the samples; lower in A and B than in C and D (P < 0.05). Storage time was significantly effective on the titratable acidity (°SH) of all Yayık butter samples (P < 0.01). The peroxide values in the samples, indicating oxidative stability, were lower than the threshold value of 2.0 meq O2/kg fat. Although not perceived sensorially, Yayık butter samples A and B had higher lipolytic activity resulting in higher free fatty acid (FFAs) accumulation, compared to C and D. Contrarily, only a very mild rancid flavor defect was pronounced for C on day 60. Among the thirty-five volatile compounds detected in the samples, the ketones (2-butanone and 2-heptanone) were predominant during the storage period. The highest amount of butyric acid was detected in A followed by D on all storage days. Sample A got the highest scores in all sensory attributes followed by sample B.

Impact of milking interval and time on milk spontaneous lipolysis and composition in dairy cows

Milk lipolysis is defined as the hydrolysis of triglycerides, the major component of milk fat, resulting in the release of short-chain fatty acids (FA) responsible for rancid flavor and partial glycerides that impair functional properties such as foaming and creaming abilities. Milk lipolysis is a complex phenomenon that depends on both animal parameters and breeding factors. Milk spontaneous lipolysis is known to be higher in milk from evening milkings than from morning milkings. This may be related to the longer length of overnight milking intervals or to the nycthemeral cycle. In this experiment, our objective was thus to study the impact of both milking intervals and time of day on milk spontaneous lipolysis in twice-daily-milking systems with one of 3 milking intervals: Short Day - Long Night (SD-LN, 6.30 a.m. and 4.30 p.m.,); Long Day - Short Night (LD-SN, 6:30 a.m. and 8:30 p.m.,); and Balanced Day and Night (BDN, 6:30 a.m. and 6:30 p.m.,). To achieve this goal, 21 multiparous dairy cows in mid-lactation were used in a 3 × 3 Latin square design over 3 periods. The experiment lasted 5 weeks, corresponding to 3 experimental periods of 6 d alternating with 8 d of milking with conventional hours (morning-evening gap of 10 h). We confirmed that milk spontaneous lipolysis was influenced by milking interval, but not the milking time. Indeed, we observed more lipolysis in SD-LN evening milk (+0.20 mEq/100 g fat) and LD-SN morning milk (+0.22 mEq/100 g fat), both of which corresponded to a 10 h interval between successive milkings. High lipolysis milk came from cows that produced less milk with a higher milk fat content. No significant difference between milkings was observed for BDN. Milk protein, total P and citrate contents increased according to the duration of mammary gland storage of milk (from 10 to 14 h). There was no effect of milking intervals on milk fat globule diameter. The milk Na+/K+ ratio, indicating an opening of tight junctions in the mammary gland, increased only in evening milkings with BDN and LD-SN. In conclusion, we found that the effect of milking intervals on lipolysis is stronger than that of the nycthemeral cycle.

Assessing the impact of dietary Camelina sativa (L.) Crantz inclusion on meat quality and sensory traits of growing rabbits

This study investigated the effects of dietary Camelina sativa oilseed cake (CSC) inclusion on the meat quality and sensory traits of growing rabbits. A total of 168 crossbred 32-day-old rabbits (both sexes) were randomly allocated into three experimental groups: a Control diet (10 % rapeseed oilseed cake as main crude protein source), CS5 diet (5 % rapeseed oilseed cake and 5 % CSC), and CS10 diet (10 % CSC). After slaughter (74 days of age), longissimus lumborum (LL) muscles and hind legs (HL) were dissected and their meat were evaluated for physical traits (LL and biceps femoris; BF), sensory attributes (LL), proximate composition and fatty acid (FA) profile (whole HL). The CSC inclusion did not significantly affect physical meat traits, except for yellowness, which decreased (P < 0.05) in both BF and LL muscles. Meat water content decreased linearly with CSC inclusion (P < 0.05). The FA profile of the HL meat was modified in rabbits fed CSC-containing diet: decreased saturated FA (P < 0.001) and monounsaturated FA (P < 0.001) and increased polyunsaturated FA (P < 0.001). Omega-3 FA content linearly increased with the CSC inclusion level (P < 0.001) and, consequently, the n-6/n-3 ratio decreased (halved ratio in CS10 compared to Control; P < 0.001). The CS10 treatment had the highest fatty flavour, rancid flavour, abnormal flavour intensity, and overall flavour intensity. However, overall acceptance was not affected. These findings suggest that CSC can be a viable protein source for sustainable rabbit production and healthy meat for consumers.

The effect of liquid smoked flavourings and wood smoke on the quality of smoked mackerel fillets during chilled storage

This study was undertaken to evaluate the effects of liquid smoked flavourings and wood smoke on the sensory, color, texture, and lipid stability of smoked mackerel fillets for four weeks chilled storage. Fish fillets were smoked by two methods: (1) immersed in brine (1:1) containing 100 g/L NaCl at 0-5 °C for 3 hours, allowed to drain at room temperature (~20 °C) for 2 hours and smoked directly with wood smoke in a smoking chamber at 25 °C for 3 hours; (2) immersed in brine (1:1) containing 5 mL/L commercial liquid smoke flavourings and 60 g/L NaCl for 16 hours at 0-5 °C then dried at 25 °C for 2 hours in an oven. Smoked samples were then vacuum packed and stored chilled at -1 °C for one week, followed by 4±1°C for three weeks. The quality changes in sensory, color, texture, and lipid stability were observed after 0, 1, 2, 3 and 4 weeks of storage. The results showed that, smoked mackerel using commercial liquid smoked flavourings was higher in rancid flavour, lightness, redness, and yellowness but had less bitter odour and was softer than the wood smoked mackerel. The lipid oxidation was higher after the wood smoke process but was however rather stable during the chilled storage. In contrast, lipid oxidation in the liquid smoked products increased significantly during chilled storage. Keywords: Atlantic mackerel (Scomber scombrus), color, liquid smoked flavouring, lipid quality, sensory, texture, wood smoke

Effect of Potentilla anserina L. powder on gel properties and volatile flavor characteristics of silver carp surimi.

Potentilla anserina L. is rich in various nutrients, active ingredients and unique flavor, comprising a natural nutrition and health food. However, its application in aquatic food has been rarely reported. Therefore, the effects of Potentilla anserina L. powder (PAP) on gel properties and volatile flavor profile of silver carp surimi were investigated. The gel strength and water-holding capacity of the surimi gels were significantly improved (P < 0.05), and the whiteness and cooking loss of all the samples decreased slightly with the increase in PAP content. The addition of PAP shortened the relaxation time (T2) of the surimi gels and converted some of the free water into immobile or bound water, which resulted in a better immobilization of water in the surimi. Scanning electron microscopy images demonstrated that the network of surimi gels with PAP added was denser and had a smoother surface compared to the control. Volatile components (VCs) analysis showed that 33 VCs were identified in the surimi gel samples with different additions of PAP, among which aldehydes, alcohols and esters were the major VCs, accounting for more than 50% of the VCs in the surimi gels. PAP addition reduced the fishy and rancid flavor compounds in surimi gels, such as 1-propanol, 1-octen-3-ol, etc., and promoted the production of aldehydes, alcohols, esters and other flavor substances. These results of the present study provide theoretical support for the investigation and development of new nutrient-health-flavored surimi products. © 2024 Society of Chemical Industry.

Consumer Acceptance Studies of Margarine to Guide Product Development in the Food Industry.

Margarine exhibits significant variations in composition, allowing it to cater to diverse consumer segments. This study aimed to characterize the physical and sensory attributes of margarine samples available in the Brazilian market. Twelve commercial samples from six different brands, encompassing 30% to 80% of lipid contents, were subjected to instrumental texture analysis and affective assessment. A total of 112 consumers participated in acceptance tests and Check-All-That-Apply (CATA) evaluations, while another group of 62 subjects performed Projective Mapping. Samples with lipid percentages exceeding 70% achieved the highest average acceptance scores for taste and overall impression. The brand with the lowest lipid content (30%) exhibited a stronger association with negative attributes, including rancid flavor and aroma, bitterness, and metallic flavor, resulting in lower average scores for aroma, flavor, texture, and overall impression. However, these scores were not statistically different from samples with 50% and 60% lipid content. Reducing lipid levels in fat-based products such as margarine poses a challenge to food manufacturers, as consumers generally perceive higher lipid percentages as indicative of superior flavor quality.

A Mini Review on Technique of Milk Thermization

Thermization is a preheating procedure in which milk is heated at low temperatures for a brief time prior to further processing. It is often used in the dairy processing industry to make a variety of products, including pasteurized milk, milk powder, and cheese. Eliminating psychrophilic bacteria, avoiding milk spoiling, and halting the changes generated by lipase and protease enzymes are the objectives of this method. Despite the fact that thermization enhances the shelf life of milk, it may also result in sensory changes and the germination of B. cereus spores. The goal of the thermization method is to prepare milk for the upcoming processing stage, and the temperature and length of the process might vary. Thermization does not affect the flavor of milk or dairy products such as yogurt, but it may enhance the quality of cheese by decreasing the occurrence of stale and rancid flavors. The process may be carried out in a plate heat exchanger or as a pre-pasteurization treatment for raw milk to protect milk quality during lengthy storage in insulated silos.

Process Parameters Optimization for Continuous Infrared Rice Bran Stabilizer and Assessment of Their Impact on Quality and Shelf Life

Background: Rice bran is the most valuable by-product of the rice milling operation. The FFA level rises immediately after milling and bran oil becomes hazardous for consumption owing to its lower pH, rancid flavor and soapy taste. Methods: A continuous-type infrared rice bran stabilizer was designed and process parameters such as moisture content, thickness, power density and treatment time were optimized for their impact on FFA content of bran, capacity and energy demand of the stabilizer using response surface methodologies. Under constant power density and moisture content, it has been confirmed that the capacity decreases with infrared exposure time. Result: The capacity was minimum (6.7 kg/h) at 0.5 cm thickness and 5 min exposer times, whereas it was maximum (40.2 kg/h) at 1 cm bed thickness and 3 min exposer time. The energy demand rose as the power density and time of exposure increased while the bed thickness and moisture content remained constant, whereas the FFA lowered nonlinearly as the power density and exposure time increased. FFA content was shown to be low at lower bed thickness and moisture content and to increase slowly as thickness and moisture content increased to 0.8 cm and 15% (w.b), respectively. However, when bed thickness and moisture level increase further, FFA content raised dramatically.

Feed restriction as a tool for further studies describing the mechanisms underlying lipolysis in milk in dairy cows

Milk lipolysis is defined as the hydrolysis of triglycerides, which are the main component of milk fat. Short-chain fatty acids (FAs) released in milk are responsible for rancid flavour. In addition, the presence of partial glycerides impairs the functional properties of milk, such as foaming and creaming abilities. Milk lipolysis, a key criterion used to assess milk quality, depends on animal parameters and breeding factors. Low-energy diets are associated with higher levels of spontaneous lipolysis, particularly in late lactation. In this study, dairy cows were fed a restricted diet (i.e. 65% of their ad libitum DM intake (DMI)) to induce spontaneous lipolysis in milk and to study milk composition associated with lipolysis. Two groups of 22 cows each received a control diet (100% of ad libitum DMI) or the restricted diet according to a 2 × 2 crossover design. The restricted diet was fed for five days. As expected, feed restriction increased milk spontaneous lipolysis which was associated with an increase in lipoprotein lipase activity. At the same time, milk yield and protein content decreased and no effect was observed on milk fat content. The increase in spontaneous lipolysis was associated with an increase in milk fat globules diameter, without influencing casein micelles diameter. Feed restriction altered the parameters of dairy cow metabolism, with increases in plasma non-esterified FAs, triglycerides and urea, indicating body fat mobilisation and protein catabolism associated with feed restriction. Feed restriction also altered hormonal parameters, with decreases in plasma insulin, insulin-like growth factor 1 and prolactin. As expected, lipolysis was higher in evening milk and was associated with a larger diameter of milk fat globules. This zootechnical approach will be completed with proteomic, lipidomic and transcriptomic studies of milk and/or mammary gland of animals selected for their extreme lipolysis.

Novel biphasic gels can mimic and replace animal fat in fully-cooked coarse-ground sausage

Four biphasic gels (BPG) were developed and tested as pork fat replacers in coarse-ground fully-cooked sausages. An oleogel (OG) phase (92.5% high-oleic soybean oil, 7.5% rice bran wax) and one of two hydrogel (HG) phases (water and 7% or 8% gelatin) were combined in 7:3 or 6:4 OG:HG ratios, for a total of four test formulations. Control sausages were formulated to 27.5% fat and stored at 0–2 °C for 98 d. BPGs allowed for fat reductions of up to 26%. Visually, all BPGs resembled pork fat. There were no differences in external L* and a* but, internally, controls were darker and redder. Except for one control, there were no differences in Texture Profile Analysis (TPA) hardness, cohesiveness, springiness, and chewiness. Warner-Bratzler Shear (WBS) force was highest in 6:4 samples, which were also highest in Sensory First Bite Firmness and lowest in Smoked Sausage Aroma and Smoked Sausage Flavor. TBARS values remained steady, with no rancid flavors detected by the sensory panel.

Shelf life of sodium-reduced ready-to-eat fish product made with by-products from fish and fruit processing subjected to high-intensity ultrasound

This study aimed to determine the shelf life by evaluating physicochemical, microbiological, and sensory parameters of spam-like cooked product made with Nile tilapia mechanically separated meat (MSM) and yellow passion fruit albedo flour (PF) submitted to sodium reduction (47.83%) and optimal high-intensity ultrasound treatment previously determined for this fish product (12.12 W/cm2 for 49 min) and stored at 4 °C for 35 days. Lipid (from 1.06 to 5.19 malondialdehyde - MDA/kg) and protein (4.68 to 9.35 nmol of carbonyl/mg of protein) oxidation increased significantly over time resulting in rancid flavor and odor formation, loss of characteristic texture and color, making the product pale and unattractive to consumers between 28 and 35 days. Twenty-one days was considered the maximum limit to store this sodium-reduced ready-to-eat fish product at 4 °C considering all evaluated parameters, which were satisfactory in this storage time.

Analysis of the trend of volatile compounds by HS-SPME-GC-MS and the main factors affecting the formation of rancid odor during the oxidation process of infant nutrition package.

In this study, headspace solid-phase micro-extraction (HS-SPME) coupled with GC-MS was used to analyze the trend of volatile compounds in fresh and oxidative infant nutrition package. Among the volatile compounds, aldehydes and ketones, alcohols, lipids, cycloalkenes, alkanes, alkenes, aromatic hydrocarbons, oxygenated compound were identified. A total of 65 volatile compounds were detected in the fresh nutrition package, whereas 9 new volatile compounds were detected during the accelerated oxidation process, which was oxidized at 45°C for 4weeks. The main components of the rancid flavor formed and the relative content of volatile substances gradually changed during the accelerated oxidation process. The volatile substances hexanal, nonanal, and 2-pentylfuran substantially increased. Linalool, α-terpineol, d-limonene, and 1-methoxy-nonane presented an evidently downward trend. The relative content of the newly formed compound 3-hydroxy-2-methylpyran-4-one during the oxidation process was always large, its relative content initially increased, then decreased, and finally increased again. The formation of rancid flavor of the nutrient package was speculated to have been formed by the interaction of hexanal, nonanal, 2-pentylfuran, and 3-hydroxy-2-methylpyran-4-one.

Terpenoids and Polyphenols as Natural Antioxidant Agents in Food Preservation.

Synthetic antioxidant food additives, such as BHA, BHT and TBHQ, are going through a difficult time, since these products generate a negative perception in consumers. This has generated an increased pressure on food manufacturers to search for safer natural alternatives like phytochemicals (such as polyphenols, including flavonoids, and essential oils rich in terpenoids, including carotenoids). These plant bioactive compounds have antioxidant activities widely proven in in vitro tests and in diverse food matrices (meat, fish, oil and vegetables). As tons of food are wasted every year due to aesthetic reasons (lipid oxidation) and premature damage caused by inappropriate packaging, there is an urgent need for natural antioxidants capable of replacing the synthetic ones to meet consumer demands. This review summarizes industrially interesting antioxidant bioactivities associated with terpenoids and polyphenols with respect to the prevention of lipid oxidation in high fat containing foods, such as meat (rich in saturated fat), fish (rich in polyunsaturated fat), oil and vegetable products, while avoiding the generation of rancid flavors and negative visual deterioration (such as color changes due to oxidized lipids). Terpenoids (like monoterpenes and carotenoids) and polyphenols (like quercetin and other flavonoids) are important phytochemicals with a broad range of antioxidant effects. These phytochemicals are widely distributed in fruits and vegetables, including agricultural waste, and are remarkably useful in food preservation, as they show bioactivity as plant antioxidants, able to scavenge reactive oxygen and nitrogen species, such as superoxide, hydroxyl or peroxyl radicals in meat and other products, contributing to the prevention of lipid oxidation processes in food matrices.

Finishing season and feeding resources influence the quality of products from extensive-system Gascon pigs. Part 2: muscle traits and sensory quality of dry-cured ham

The quality of pork products from local breeds in extensive systems depends, among other things, on pig production. In particular, the variability in climatic conditions and feeding resources may influence the properties of tissues at slaughter and the quality of pork and processed products. The present study (part 2) was part of a larger project that assessed the influence of the finishing season and feeding resources on carcass and tissue traits and the quality of meat and dry-cured ham from Gascon pigs in an extensive system. Following the specifications of the Protected Designation of Origin “Noir de Bigorre”, castrated Gascon males were reared on rangelands (grassland and forest areas) and received a supplementary diet from 5 to 6 months of age until slaughter at a minimum of 12 months and ca. 170 kg BW. Three finishing seasons were considered: Winter (n = 18), Spring (n = 22) and Autumn (n = 23). To estimate the specific effects of season on quality traits and avoid bias due to effects of genes known to influence these traits, polymorphisms in the RYR1, PRKAG3, MC4R and LEPR genes were included in the analysis models. Compared to Winter pigs, Spring and Autumn pigs had higher ultimate pH in the semimembranosus and gluteus medius (GM) muscles, lower meat lightness (P < 0.05) and tended to have higher GM intramuscular fat (IMF) content (P < 0.10). They also had higher GM contents of saturated, monounsaturated and polyunsaturated fatty acids (FAs) than Winter pigs (P < 0.05). Spring pigs had the lowest n-6:n-3 polyunsaturated FA ratio and the highest GM α-tocopherol content (P < 0.001), indicating pig grazing. The finishing season did not influence the processing yield of dry-cured hams (24-month process). Within each seasonal group, ten hams selected for genetic variability and IMF content were analyzed by a trained sensory panel. The season did not modify the appearance or odor, but influenced texture and taste. Hams from Winter and Spring pigs had higher tenderness and melting fat scores than hams from Autumn pigs (P < 0.01). Hams from Spring pigs had higher taste intensity and salty taste (P < 0.01) but lower positive tastes (e.g. fruits, forest) than hams from the other groups. Overall, finishing season had moderate effects on ham sensory traits. Furthermore, our results reveal high redness, tenderness, taste and odor intensity, and low rancid flavor of hams from Gascon pigs produced in an extensive system.

Effect of Feeding Barley, Corn, and a Barley/Corn Blend on Beef Composition and End-Product Palatability.

This study evaluated the relationship among palatability attributes, volatile compounds, and fatty acid (FA) profiles in meat from barley, corn, and blended (50:50, barley and corn) grain-fed steers. Multiple correspondence analysis with three dimensions (Dim) explained 62.2% of the total variability among samples. The Dim 1 and 2 (53.3%) separated pure from blended grain-fed beef samples. Blended grain beef was linked to a number of volatiles including (E,E)-2,4-decadienal, hexanal, 1-octen-3-ol, and 2,3-octanedione. In addition, blended grain-fed beef was linked to fat-like and rancid flavors, stale-cardboard, metallic, cruciferous, and fat-like aroma descriptors, and negative categories for flavor intensity (FI), off-flavor, and tenderness. A possible combination of linoleic and linolenic acids in the blended diet, lower rumen pH, and incomplete biohydrogenation of blended grain-fed polyunsaturates could have increased (p ≤ 0.05) long-chain n-6 fatty acids (LCFA) in blended grain-fed beef, leading to more accumulation of FA oxidation products in the blended than in barley and corn grain-fed meat samples. The Dim 3 (8.9%) allowed corn separation from barley grain beef. Barley grain-fed beef was mainly linked to alkanes and beef positive FI, whereas corn grain-fed beef was associated with pyrazines, in addition to aldehydes related to n-6 LCFA oxidation.

Postmortem Aging Time and Marbling Class Effects on Flavor of Three Muscles From Beef Top Loin and Top Sirloin Subprimals

This study evaluated postmortem aging time and marbling class effects on flavor attributes of longissimus lumborum, gluteus medius, and biceps femoris steaks. Carcasses selected to have Lower Small (Small00 to Small49; n = 50) or Upper Slight (Slight50 to Slight99; n = 50) marbling were assigned to aging treatments (14, 21, 28, or 35 d) in an incomplete block arrangement. A trained sensory panel evaluated longissimus lumborum, gluteus medius, and biceps femoris steaks for tenderness, juiciness, and 31 flavor notes. Tenderness increases with aging time were linear (P &amp;lt; 0.001) in longissimus lumborum and gluteus medius steaks and quadratic (P = 0.001) in biceps femoris steaks. Aging response of rancid flavor in longissimus lumborum steaks was cubic (P = 0.01), whereas the aging response of bloody/serumy flavor in biceps femoris steaks was quadratic (P = 0.03). Compared with Upper Slight marbling, carcasses with Lower Small marbling produced longissimus lumborum steaks with greater (P &amp;lt; 0.01) beef flavor and lesser (P = 0.001) bitter flavor, gluteus medius steaks with greater (P = 0.05) brown/roasted flavor, and biceps femoris steaks with greater (P = 0.02) fat-like flavor, although differences were small. Principal component analysis indicated that bloody/serumy, sour, metallic, and bitter flavor attributes were the strongest contributors to a factor explaining 38% of longissimus lumborum flavor variation. Barnyard, bitter, sour, rancid, and bloody/serumy were the greatest contributors to a principal component explaining 41% of gluteus medius flavor. Barnyard, rancid, sour, bloody/serumy, and bitter were contributors to a component explaining 63% of biceps femoris sirloin cap flavor variance. Sample score plots indicated that neither aging time nor marbling class was associated with principal components and identified production lot as contributing to principal components explaining flavor variation in all 3 muscles. Results indicate that, in strip loin and top sirloin subprimals from carcasses with Upper Slight and Lower Small marbling scores, aging time and marbling class had little impact on beef flavor. Thus, increased aging times could be used to enhance tenderness with no adverse effects on other important palatability attributes.

Impact of frozen temperature and thawing methods on the Brazilian sensory profile of Nellore beef

We evaluated the effect of frozen storage temperature and thawing methods on acceptance and sensory profile of steaks of Nellore beef strip loin under 30 days of frozen storage. Fresh strip loin (n = 13), collected two days after slaughter, were aged (2 °C) for 14 days and cut into seven steaks subjected to one of the treatments: control (unfrozen), combination of two freezing temperatures (−10 and −20 °C), and three thawing methods (microwave, ambient temperature, and refrigeration thawing). Steaks in the frozen/thawing treatment were frozen using an ultra-fast freezer until the desirable temperature was reached and were stored for 30 days. After cooking, steaks were analyzed by 11 panelists for the Quantitative Descriptive Analysis (QDA®) and by 120 beef consumers for acceptance. Storage temperature and thawing methods showed little or no changes in the sensory quality of strip loin steaks, detected by either panelists or consumers. In the QDA®, apparent juiciness was lower in samples thawed in microwave, while the rancid flavor was lower for samples frozen at −20 °C and thawed in refrigeration ( p < 0.05). The consumer test showed that samples stored at −10 °C and microwave thawing was most accepted in terms of tenderness, juiciness, and overall impression. Fresh steaks (unfrozen) had low acceptance for overall impression in relation to frozen meat. This indicates that consumers could use a household freezer (−10 °C) and quicker thawing methods (microwave or room temperature) without compromising the sensory perception of steaks frozen up to one month.

Efecto de la suplementación con selenio orgánico sobre la calidad de la canal y la vida útil de la carne de vaquillonas terminadas en feedlot

The objective of this work was to evaluate the effect of organic selenium supplementation (Selplex®) on heifer’s carcass quality and meat shelf life in a feedlot system. Thirty Hereford heifers were used: 14 of 20 months of age, with an initial weight of 323 ± 26.27 kg, and 16 of 36 months and 405 ± 30.52 kg. Animals were housed in individual pens and drawn within each age category to 2 treatments: Control and Supplementation with organic selenium at a rate of 0.9 mg Se/kgDM/day. All animals were fed a fully mixed ration (RTM) including 15% moha bale (Setaria italica) and 85% commercial ration for fattening cattle. Animals were slaughtered after 62 days of feeding. Color evolution, lipid and protein oxidation were measure on sample packed using an oxygen permeable film and stored during 12 days in a refrigerated display case. Selenium supplementation resulted in an increase level of glutathione peroxidase (GSH-Px) (195.9 vs 259.7 U/gr Hg, p<0.0001), a decrease lipid oxidation (0.65 vs. 0.57 mg MDA/kg) (p<0.05) and shear force after 7 days of ageing (3.22 vs. 2.68 kg) (p<0.05). Twenty months heifers supplemented with selenium achieved higher levels of GSH-Px (242 vs. 213 U/gr Hg) (p<0.05) and was detected a lower rancid flavor in relation to those of 36 months (2.9 vs. 3.6) (p<0.05). Organic selenium supplementation may be an alternative to decrease meat lipid oxidation, however it had no effect on color evolution and in reducing protein oxidation (0.31 vs.0.35 nmoles/mg) (p ≥ 0.05).

Influence of Reheating Methods and Frozen Storage on Physicochemical Characteristics and Warmed-Over Flavor of Nutmeg Extract-Enriched Precooked Beef Meatballs.

The effects of convection-oven precooking, frozen storage (−18 °C/ two months) and four different reheating methods—namely, boiling, pan-roasting, convection oven and microwave oven on pH, color, texture, antioxidant activity and warmed-over flavor of beef meatballs were investigated. In this study, four kinds of beef meatballs were prepared: with added butylated hydroxyl toluene (0.02% BHT, M1); with nutmeg extract (0.02%, M2); with nutmeg powder (0.02%, M3) and control (no antioxidant). Addition of (0.02%) nutmeg extracts in beef meatballs M2 resulted in a significant (p < 0.05) decrease in lipid and protein oxidation, hardness and gumminess values after convection oven precooking. Again, M2 reheated by microwave oven significantly (p < 0.05) reduced cooking loss, gumminess, springiness, rancid flavor, saltiness and burnt taste and increased oxidative stability, redness and adhesiveness with the chewiness intensity and overall acceptability compared to control, M1 and M3. Conclusively, the addition of nutmeg extracts (0.02%) as a natural plant antioxidant to precooked beef meatballs can result in reduced lipid and protein oxidation levels, stabilized color and texture values and improved overall acceptance after reheated by microwave oven during two months of frozen storage.

Storage stability of osmotic dehydrated coconut

Acidified salt solution and sugar solution were used as osmotic agents for the processing of osmotic dehydrated coconut. The free fatty acid content of control sample was 0.410 per cent (% of oleic acid) and increased to 1.186 per cent (% of oleic acid) between 0 and 180 days. The oleic acid content of T1 and T2 were ranged between 0.401 to 0.581 and 0.381 to 0.483 per cent of oleic acid, respectively. The rancid flavour was felt in the control sample and a drastic changes in the taste was also found, which reduced its score value from 4.0 to 2.0 during the storage. The microbial load of bacteria, fungi and actinomycetes present in the dehydrated coconut were between the ranges of 3.0 to 7.0 CFU/g x 106, 1.0 to 4.0 CFU/g x 102 and 1.0 to 6.0 CFU/g x 103, respectively.