Warmed-over Flavor Research Articles

Yeast extracts weakened warmed-over flavor in surimi gels made from silver carp due to the masking effect by high concentrations of pyrazines and esters.

Warmed-over flavor (WOF) is an off-flavor in surimi gels. Yeast extract (YE) could improve the aroma properties of food. However, the effect of YE on the WOF in surimi gels and its mechanism was still unclear. In this study, aroma profiles, the composition of aroma compounds and aroma precursors, concentrations of WOF compounds, and thiobarbituric acid reactive substances (TBARS) of surimi gels with different amounts of YE were investigated by molecular sensory science and chromatographic techniques. Moreover, the effect of pyrazines and esters introduced by YE on WOF was also tested by sensory analysis. The addition of no less than 1% YE to surimi gels significantly weakened WOF. However, YE did not decrease the concentrations of WOF compounds and did not change the fatty acid composition and TBARS in surimi gels. Conversely, the addition of YE significantly increased the contents of free amino acids, N-containing compounds, and esters in surimi gels. The contents of total free amino acids, 2,6-dimethylpyrazine, and ethyl acetate in surimi gels with 2.5% YE were 1.5, 21, and 2.1 times higher than those in the control, respectively. Additionally, the sensory results of the spiked aroma models containing WOF compounds, 2,6-dimethylpyrazine, and esters showed that more than 9.4µg/kg of 2,6-dimethylpyrazine with a baked-potato note and more than 6.1µg/kg of ethyl acetate and 11.2µg/kg of butyl acetate with a fruity note could significantly mask WOF. In conclusion, WOF in surimi gels could be masked by YE due to the high concentrations of pyrazines and esters. Practical Application: Yeast extracts could decrease the warmed-over flavor (WOF) due to the high concentrations of pyrazines (baked-potato note) and esters (fruity note). This finding extends the application of yeast extracts in the food industry. On the other hand, this study presents a reasonable solution for the reduction of WOF in surimi products.

Perilla juice and ginger juice reduced warmed-over flavor (WOF) in surimi gels: Due to the inhibition of the formation of the WOF compounds and the masking of the WOF

The effects and reasons of perilla juice (PJ) and ginger juice (GJ) on the reduction of “warmed-over flavor” (WOF) in surimi gels were revealed by detecting odor profiles and protein and lipid oxidation degrees of surimi gels, concentrations and odor activity values (OAVs) of WOF compounds. Adding PJ and GJ to surimi gels significantly reduced the WOF and improved the fish fragrance odor, but sodium ascorbate (SA) only weakened the WOF. The (E,E)-2,4-heptadienal's OAVs in the PJ and GJ groups were decreased by >50% compared with the control check (CK) and SA groups. Meanwhile, surimi gels added with PJ and GJ presented lower lipid and protein oxidation degrees. The verification test indicated that PJ and GJ's aroma had a masking effect on the WOF. In conclusion, PJ and GJ reduced the WOF in surimi gels by preventing WOF compounds' production and masking the WOF with their distinct aroma.

Effect of low-dose blanched Saccharina latissima in finishing bulls’ diets on carcass and meat quality traits

Nutritional and bioactive compounds present in seaweeds make them suitable supplements or feed ingredients in livestock diets. This study assessed the effect of blanched seaweed (Saccharina latissima) as a supplement in finishing bulls’ diets on carcass traits and the quality of the longissimus lumborum (LL) and semimembranosus (SM) muscles. A concentration of 0.8% dry matter of blanched S. latissima in bulls’ diets was the maximum amount allowed, owing to iodine and arsenic thresholds in animal feed. Nineteen Limousin crossbreed bulls were randomly assigned to two groups, fed a control (CD, n = 9) diet or a test diet supplemented with blanched seaweed (SW, n = 10), and fed for 48 days pre slaughter. The carcasses from the bulls finished on a seaweed-supplemented diet were heavier (p < 0.05) than those in the control group, while levels of conformation and fatness were similar between the groups (p > 0.05). The pH was lower (p < 0.05) in the LL of CD-fed animals in early post mortem than in the LL of SW-fed animals, whereas no differences (p > 0.05) were found in the ultimate pH. The meat from the bulls fed both diets had a similar (p > 0.05) drip loss and shear force at days 7 and 14. The cooking loss at day 7 was not affected (p > 0.05) by diet, whereas on day 14 the cooking loss was greater (p < 0.05) for SW than for CD meat. Warmed-over flavor and shear force were muscle dependent and lower (p < 0.05) for LL than SM. Seaweed supplementation in finishing bulls’ diets had no clear effect on color changes (L*, a*, and b* values) during chilled storage, although reduced b* values (p < 0.05) suggest an improved color stability of meat from SW- compared with CD-fed animals. The iodine content was higher (p < 0.05) in the SW meat than in the CD meat, even when using the low seaweed supplementation level requested by the authorities. A small increase of arsenic in the meat with seaweed supplementation has no implications on human health. Cost-efficient processing methods for the further reduction of iodine and arsenic are needed to increase the utilization of seaweed as a feed additive/ingredient and attain a clear effect on meat quality.

Descriptive Beef Flavor Attributes and Consumer Acceptance Relationships for Heavy Beef Eaters

Differences in beef flavor attributes were created using beef cuts (Choice M. gluteus medius (GM) steaks; Choice M. biceps femoris (BF) roasts; Select BF roasts; Choice M. longissimus lumborum (LM) steaks, and high pH LM steaks), cooking method, and internal cook temperature endpoint (END). Steaks were cooked to 58°C and 80°C END utilizing either a George Foreman clamshell grill (GF) or a flat top electric food-service grill (GRILL). Roasts were cooked at low temperatures using a Crock-Pot (CP) cooking to 58°C and 80°C END. Thirty-seven flavor descriptive attributes were evaluated by an expert, trained descriptive beef flavor panel. Heavy beef eaters were recruited in Houston, TX; Olathe, KS; Philadelphia, PA; and Portland, OR. Consumers evaluated overall, flavor, beef flavor, and grill flavor liking using 9-point hedonic scales and beef flavor, grill flavor and off-flavor intensity using 9-point intensity scales. Steaks and roasts differed in descriptive and consumer attributes (P < 0.05). Treatments with higher levels of fat-like, salt, beef identity, and brown/roasted flavor attributes had higher consumer liking ratings (Choice LM or GM GRILL steaks cooked to 58°C or 80°C and Choice GM GRILL steaks cooked to 80°C). Select and Choice BF CP roasts cooked to 58°C or 80°C, Choice GM GF steaks cooked to 80°C, and high pH LM GF steaks cooked to 80°C had the lowest consumer liking scores and higher levels of warmed-over flavor, cardboardy, and liver-like flavor attributes. Heavy beef consumers segmented into 4 classes. Class 4 consumers liked beef regardless of treatment, whereas Class 3 consumers were discerning. Heavy beef eaters discerned differences in beef flavor attributes, and beef flavor was a driver of consumer liking.

Investigation of the effect of chemical composition of surimi and gelling temperature on the odor characteristics of surimi products based on gas chromatography-mass spectrometry/olfactometry

This study investigated the effects of chemical composition of surimi (prepared by 0, 1, or 2 times of rinsing) and gelling temperature (90 °C and 100 °C) on the odor characteristics of surimi products and the relationship between the chemical composition of surimi and the aroma of surimi products. The once- and twice-rinsed surimi showed a decrease (p < 0.05) of 71.32%, 74.60%, 42.79% and 61.12% in the contents of total amino acids and total fatty acids, respectively. The surimi products prepared with un-rinsed surimi at 90 °C had the highest fish-fragrance score, while those prepared with once-rinsed surimi at 100 °C showed the strongest warmed-over flavor (WOF) and the lowest fish-fragrance score.Gly, Phe, and most of the saturated fatty acids were associated with WOF formation in surimi products, while Leu, Ile, Val, Asp, and unsaturated fatty acids were positively related to their fish-fragrance note.

Warmed-over flavour profiles, microbial changes, shelf-life and check-all-that-apply sensory analysis of cooked minced pork treated with varying levels of Moringa oleifera leaf and root powder

This study investigated warmed-over flavour profiles, microbial changes, shelf-life and sensory characteristics of minced cooked pork treated with Moringa oleifera (M. oleifera) root and leaf powder during refrigerated storage at 4 °C. A total of 8 treatments (control = no antioxidant; 0.5ML = 0.5% M. oleifera leaf; 1ML = 1% M. oleifera leaf; 0.5MR = 0.5 % M. oleifera root; 1MR = 1% M. oleifera root; 0.5MLR = 0.5% M. oleifera leaf and root mixed; 1MLR = 1% M. oleifera leaf and root mixed; BHT = 0.02% butylated hydroxytoluene) were evaluated. The minimum inhibitory concentration (MIC) of the plant extracts against the test bacteria was determined using the serial dilution in 96 well microtiter plates technique. Warmed-over flavour profiles were determined using the test for carbonyls assay where hexanal was used as a marker for warmed-over flavour. The check-all-that-apply sensory tool was used to characterise minced cooked pork treated with different antioxidants according to warmed-over flavour taste and odour intensities. The results showed that the antibacterial assay of the extracts exhibited a broad-spectrum of activity against the tested bacteria. The leaf extracts demonstrated better activity against both gram-negative and gram-positive bacteria, with most of the MICs at less than 1 mg/mL, while the root performed better against gram-negative bacteria compared to gram-positive bacteria. There was a significant rapid increase in the warmed-over flavour profiles of the control compared to the M. oleifera and BHT treated pork. The pork samples which had M. oleifera leaf, root, and their combination at inclusion levels of 1% and 0.5% displayed lower warmed-over flavour profiles that fell in the range (1.0–1.46 mg hexanal/100g fat) throughout the storage period. Consumer sensory evaluation revealed that pork samples treated with the highest inclusion level (1%) of the M. oleifera leaf powder received the lowest consumer rating scores for appearance. Based on these results, adding M. oleifera leaf and root powder can decrease warmed-over flavour development and improve the shelf-life of processed pork. Furthermore, the incorporation of M. oleifera root powder can potentially be more acceptable to consumers because of its colour compared to the leaf, which gives the product a green colour that may not be pleasant for some consumers. This suggests that the inclusion of the root powder at 1% may be well accepted for consumption by consumers.

Characterization of Warmed-Over Flavor Compounds in Surimi Gel Made from Silver Carp (Hypophthalmichthys molitrix) by Gas Chromatography-Ion Mobility Spectrometry, Aroma Extract Dilution Analysis, Aroma Recombination, and Omission Studies.

The warmed-over flavor (WOF) in surimi gels was characterized by gas chromatography-ion mobility spectrometry, aroma extract dilution analysis, aroma recombination, and omission studies. Surimi gels with different WOF levels were prepared by different gelling temperatures, and surimi gels heated at 90, 100, and 121 °C were considered as the samples with light, strong, and medium WOF, respectively. Based on the quantification and odor activity values, 14 aldehydes, 2 ketones, 3 alcohols, 2 benzene-containing compounds, 2 N-containing compounds, 3 S-containing compounds, 3 lactones, undecanoic acid, and 4-methylphenol were recombined to build a spiked model for surimi gels with the strongest WOF, which showed the highest similarity with the original sample. Finally, a triangle test involving omission of the aroma compounds from the spiked model proved that the WOF in surimi gels was attributed to (E,E)-2,4-decadienal, heptanal, octanal, nonanal, decanal, (E)-2-nonenal, (E)-2-octenal, (E)-2-decenal, (E,E)-2,4-heptadienal, 2,3-pentanedione, 2,6-dimethylpyrazine, 2-propylpyridine, benzothiazole, 2-methoxybenzenethiol, and 2-furfurylthiol.

Changes in volatile profiles of a refrigerated-reheated xylose-cysteine-lecithin reaction model analyzed by GC×GC-MS and E-nose.

The changes in the volatile profiles of a xylose-cysteine-lecithin reaction model were investigated by using comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) in combination with headspace solid-phase microextraction (SPME) and electronic nose (E-nose) to evaluate the contribution of refrigerating and reheating treatment to warmed-over flavor (WOF). The volatile compound results and E-nose revealed that the contribution of refrigerating and reheating to the WOF was not consistent. After refrigerating, the level of furfuryl mercaptan increased, while that of 1-octene-3-ol, octanal, nonanal, and 2-decanone decreased, which affected the flavors. An increase in the level of 1-octene-3-ol, 2-pentyl-thiophene, and hexanoic acid and a decrease in the levels of furfural, 2-methyl-3-furanthiol, and 2-methyl-3-pentanethiol occurred during reheating. According to the odor activity value and sensory evaluation, the sulfur-like odor became more intense after refrigerating, while the rancid-like odor grew stronger, but the sulfur-like odor alleviated after reheating. Overall, the reaction between residual substances caused the WOF during refrigeration, also lead to the fatty acid oxidation increased after reheating. The overproduction of fatty acids oxidation products and decreased of volatile product of Maillard reaction leads to the WOF during reheating. PRACTICAL APPLICATION: This study provides theoretical guidance to reduce the off-flavors of meat products.

Warmed-Over Flavour Profiles, Shelf-Life and Check-All-That-Apply Sensory Analysis of Cooked Minced Pork Treated with Varying Levels of &lt;i&gt;Moringa Oleifera&lt;/i&gt; Leaf and Root Powder

Warmed-Over Flavour Profiles, Shelf-Life and Check-All-That-Apply Sensory Analysis of Cooked Minced Pork Treated with Varying Levels of &lt;i&gt;Moringa Oleifera&lt;/i&gt; Leaf and Root Powder

Comparative characterization of fatty acids, reheating volatile compounds, and warmed-over flavor (WOF) of Chinese indigenous pork and hybrid pork

Chinese indigenous pork is preferred by consumers because of its unique nutritional and flavor characteristics. The aim of this study was to investigate the fatty acid contents and reheating volatile compounds (i.e., warmed-over flavor (WOF)) of the biceps femoris muscle of four Chinese indigenous (i.e., Guangdong small-ear spotted, GSS; hill black, HB; Beijing black, BB; Qingyu, QY) and one hybrid (i.e., Duroc × Landrace × Yorkshire, DLY) pig breeds. Principal component analysis of 20 fatty acids and 30 reheating volatiles showed that five pig breeds could clearly be distinguished from each other. Among the pig breeds studied, GSS showed the lowest WOF contents and odor activity values (OAVs) (1251.87 μg/kg and 1111.64, respectively). Differences in WOF content and OAV among the four other breeds did not significantly differ (P > 0.05). Correlation analysis demonstrated that C16:1, C18:1, and C18:2 may be the key fatty acids of WOF formation. This study provides a new strategy for reducing the WOF of precooked meat products.

Antioxidant effect of rice bran purified phytic acid on mechanically deboned chicken meat

This study aimed to evaluate the antioxidant effect of rice bran purified phytic acid (PA; 78.2%) and compare it with the standard high purity rice PA (≥90%) after added to mechanically deboned chicken meat (MDCM) and stored at −18℃ for 120 days. Rice bran purified PA (RPA) and standard PA (SPA) were added to MDCM at 5 and 10 mmol/kg and MDCM samples were analyzed for lipid oxidation by thiobarbituric acid reactive substance (TBARS), warmed-over flavor (WOF), and estimated myoglobin content at 15 days intervals for up to 120 days. RPA addition to MDCM stored for 120 days at −18℃ inhibited lipid oxidation, reducing WOF, and heme pigment oxidation that maintains the characteristic MDCM color. The results suggested that RPA is a suitable and efficient natural antioxidant in MDCM. Practical applications Mechanically deboned chicken meat (MDCM) is a poultry deboned carcass by-product and an important raw material for cooked meat production. MDCM stability is affected by bone separation, grinding process, and bone marrow content (hemoglobin-rich). The meat industry demands quality and stability improvements for MDCM due to its rapid propensity for oxidation. Phytic acid (myo-inositol hexaphosphate) is a powerful antioxidant with potential use in foods. It is efficient, safe, and naturally sourced. It alters redox potential, keeping it in Fe3+ form, protecting it against oxidative damage, thus improving the MDCM quality. The present study results are expected to contribute to the meat industry in producing safe and quality products.

Effects of phospholipids and reheating treatment on volatile compounds in phospholipid-xylose-cysteine reaction systems

Volatile compound profiles in phospholipid (lecithin and cephalin)-xylose-cysteine reaction systems before and after reheating treatment were determined by solid phase micro-extraction combined with gas chromatography-mass spectrometry to investigate the development mechanism of the warmed-over flavor. The contents of sulfides in the four groups containing added lecithin were significantly higher than those in the other groups, indicating that lecithin had a strong promoting effect on the formation of Maillard reaction products at the intermediate-end stages in the reaction system. The coexistence of phosphatidylcholine and lecithin accelerated the Maillard reaction and fatty acid oxidation. Reheating treatment could promote the simultaneous generation of final-stage Maillard reaction products, the formation of fatty aldehydes, and the reaction of fatty aldehydes with intermediate-stage Maillard reaction products of the mid-stage, which ultimately leads to a decrease in the contents of sulfursulphur-containing Maillard reaction products such as those leading to aroma and an increase in the content of aldehydes in meat and demonstrated good consistency with the results of the sensory evaluation. Odour activity values showed that decanal was the main substance contributing to the warmed-over flavor after reheating treatment in the reaction system. The decrease in meaty flavors, such as 2-methylpentane-3-thiol and furfuryl mercaptan also resulted in flavor deterioration after reheating.

Poultry breasts with white striping meat x impacts on technological properties

This work aimed to characterize the physicochemical parameters and technological properties of breasts from poultry with WS and compare them with normal breasts to evaluate breast quality. Poultry breast fillets (10 normal and 10 carcasses with WS) were White Striping (WS) is a major problem that compromise the quality of the meat. Occurrence of WS on the surface of chicken breasts impairs the visual appearance and consequently decreases consumer acceptance causing damage to the industrial sector. obtained from a slaughterhouse. Then they were weighed, packaged and stored in the freezer at -20°C until analysis of: pH, moisture, protein, lipids, lipid oxidation, warmed-over flavor (WOF), water holding capacity (WHC), cooking loss (CL), exudate protein content (EP) and myofibrillar fragmentation index (MFI) of proteins. The physicochemical characteristics and technological parameters of poultry breasts with WS compromised the quality of the product when compared to the normal breast showing heavier breasts, increasing moisture, lipid content, lipid oxidation and WOF, reduction in total protein content and WHC and an increase in CL, EP content and MFI of proteins. Therefore, this myopathy showed changes in the physical and chemical parameters that can compromise the technological and sensory aspects of meat products, affecting their quality.

Enrichment of nitrite in onion powder using atmospheric pressure plasma and egg whites for meat curing

This study aimed to evaluate the efficacy of natural nitrite sources prepared by atmospheric pressure plasma (APP) treatment on onion and egg white mixtures to replace sodium nitrite in processed meat. Onions were treated with APP alone (PO) or in the presence of 30% egg whites (w/w, POE). Although PO also showed an increase in nitrite content, the addition of egg whites during APP treatment resulted in an increase of about 4 times nitrite content in POE compared to PO. To test the practical application of this technique, emulsion sausages were prepared by adding four different nitrite sources: no nitrite source (CON), sodium nitrite (SN), PO powder, and POE powder, then sausage properties were evaluated on a consumer scale. POE sausages showed a similar nitrite content and visual redness to the sausages with sodium nitrite and acquired onion-like odor and significantly reduced warmed-over flavor (WOF). Consequently, we concluded that nitrite-enriched onion powder by egg whites addition during APP treatment has the potential to effectively replace synthetic sodium nitrite in processed sausages without compromising product flavors.

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.

Consumer exposure to warmed-over flavour and their attitudes towards the use of natural antioxidants as preservatives in meat and meat products

PurposeThe objective of the study was to assess consumer exposure to warmed-over flavour, their eating habits with respect to pre-cooked stored meats, awareness of antioxidants and attitudes towards the use of natural antioxidants as preservatives in meat and meat products.Design/methodology/approachA total of 238 Check-All-That-Apply (CATA) design questionnaires were used to gather information from the University of Fort Hare community in the Eastern Cape province of South Africa.FindingsThe majority of the respondents had been exposed to warmed-over flavour before. More than half of the respondents did not know about antioxidants. Respondents were in support of the use of natural antioxidants in meat and meat products.Research limitations/implicationsThe study mainly captured consumer habits based on living arrangements. Age influence could not be extrapolated due to the nature of the population, which was being studied. The population was limited to the University community, which is mainly made up of not so widely spread age groups and more or less similar levels of education. As a result, the findings and conclusions may not be a true reflection of the general public consumers in terms of age, level of education and employment status.Originality/valueThis research presents an original insight into consumer habits concerning the purchasing and storage of pre-cooked meat and meat products. The study revealed that most consumers nowadays prefer ready-to-eat or pre-cooked meat and meat products due to convenience. The warmed-over flavour is common in pre-cooked meats. The findings suggests that the meat industry has to improve the shelf-life of pre-cooked foods such that warmed-over flavour development is delayed to fit into the current consumer habits. In recent years there has been a growing interest in the use of natural antioxidants to improve shelf-life of muscle foods. However, there is a dearth of information on consumer attitudes towards the use of natural antioxidants as preservatives. This study reveals that consumers are willing to try products formulated using natural antioxidants.

Replacing soybean meal with rapeseed meal and faba beans in a growing-finishing pig diet: Effect on growth performance, meat quality and metabolite changes

Rapeseed meal and faba beans (RSM/FB) can serve as an alternative to imported soybean meal (SBM). In this study, forty Norwegian crossbred ([Landrace x Yorkshire] x Duroc) growing-finishing pigs (108.7 ± 4.2 kg final BW) were fed a diet with either SBM or RSM/FB as protein sources. RSM/FB increased feed conversion ratio (P = .04) in the finishing period, reduced lightness (P = .04) and yellowness (P = .004) of meat, changed amounts of individual fatty acids, but not of total SFA, MUFA and PUFA. Importantly, RSM/FB reduced the glucose level (P < .05) in meat. Lower pyroglutamic acid (P = .06) in RSM/FB indicate lower oxidative stress in pre-rigor muscle cell. Increased abundance of free amino acids, sweet tasting metabolites, reduced warmed-over flavor and flavor attributes indicated desirable properties of RSM/FB meat. To conclude, RSM/FB in pig diet supported growth performance and carcass quality comparable to SBM and had a positive effect on meat quality.

Changes in flavour compound profiles of precooked pork after reheating (warmed‐over flavour) using gas chromatography–olfactometry–mass spectrometry with chromatographic feature extraction

SummaryThe unclear components and complex evaluation indicators affect the effectiveness of inhibition methods for warmed‐over flavour (WOF). To evaluate the main components of WOF, the changes in flavour compound profiles of precooked pork after reheating were investigated quantitatively by using gas chromatography–olfactometry–mass spectrometry with chromatographic feature extraction. A total of 49 volatile compounds were identified, including 22 aroma‐active compounds that were primarily derived from lipid oxidation. Fifteen key volatile compounds were obtained that represented principal components of the changes in flavour compound profiles, of which 1‐octen‐3‐ol, (Z)‐2‐octenal and (E,E)‐2,4‐decadienal made the greatest contribution to the principal components and achieved odour activity value (OAVs) &gt;1.0 after reheating. The results showed that the three compounds are the dominant volatile compounds and potential evaluation indicators of WOF. This study provides a further understanding of the components of WOF in precooked pork and an effective analysis method of gas chromatography.

The effect of natural and synthetic antioxidants and packaging type on the quality of cooked poultry products during frozen storage.

The effect of oil-soluble rosemary extract, sodium erythorbate and their mixture, and the influence of packaging method (air and vacuum packaging) on the quality of cooked turkey meatballs stored at -20 ℃ was determined. The smallest changes in malondialdehyde content were observed in samples with the addition of the natural antioxidant regardless of the packaging method. The mixture of synthetic and natural antioxidants was more effective in retarding lipid oxidation than the synthetic antioxidant, and more desirable results were observed in vacuum-packaged samples than in air-packaged samples. The samples with the addition of oil-soluble rosemary extract were characterised by lower intensity of red colour, but this parameter was more stable during frozen storage. The results of a sensory analysis revealed that the application of oil-soluble rosemary extract with or without sodium erythorbate significantly inhibited the development of warmed-over flavour in cooked poultry products.

Evaluations of physicochemical and anti-oxidant properties of powdered leaves from lotus, shepherd's purse and goldenrod in restructured duck/pork patties.

The objective of this study was to determine the effects of powdered leaves of lotus (LP), shepherd's purse (SP) and goldenrod (GP) on oxidation stability and quality characteristics of cooked duck/pork patties. Fresh duck tenderloin (M. pectoralis) and pork meat (M. biceps femoris, semitendinosus, and semimembranosus) were ground, formulated with LP, SP, GP or butylated hydroxytoluene (BHT), and mixed with other non-meat ingredients. The manufactured patties were cooked, packaged, and stored at 3°C for 4weeks. The patties containing 1% of LP, SP and GP had significantly lower values in redness, thiobarbituric acid reactive substances, conjugated dienes and total volatile basic nitrogen compared to control. No significant differences in sensory tenderness between the control and treated samples were observed. Addition of LP had a similar warmed-over flavor extent compared to patties with BHT. These results indicate that incorporation of the natural leaves could effectively inhibit oxidation and maintain freshness of cooked patties without any detrimental effects on sensory attributes during storage.