Utilization of Rice Starch in the Formulation of Low-Fat,Wheat-Free Chicken Nuggets

Three trials of 6 treatments (rice flour, wet batter baked; rice flour, dry batter baked; rice flour, wet batter fried; wheat flour, wet batter baked; wheat flour, dry batter baked; wheat flour, wet batter fried) were utilized to test the effects of flour type, batter type, and cooking method on the characteristics of chicken nuggets. Value was added to these chicken nuggets by utilizing rice flour in the production of gluten-free products as well as lipid reduction through baking. Added value is attributed to the production of a product that is highly acceptable to certain consumer clusters and has the potential to reach niche markets (wheat-free or low-fat chicken nuggets) that have not previously been targeted in the mainstream portion of the grocery store. Consumers were clustered into 6 population segments revealing that all 6 treatments were acceptable to some segment of the population. Baking instead of frying reduced fat calories by at least 67%. This reveals the feasibility of using rice flour in the formulation of low-fat or wheat-free chicken nuggets without diminishing quality and the added value component of usability by people who either require a low-fat diet, have celiac disease, or both.     

Chemical composition and nutritional value in vitro of mechanically‐deboned poultry meat

1. The composition by proximate analysis, amino acid content and digestibility by mammalian proteolytic enzymes of pastes from mechanically‐deboned chicken breasts wings, necks and backs, and hand‐deboned breast were measured. Values obtained were used to calculate indices of nutritional value.

2. All pastes compared favourably with similar protein materials used for human food. Mechanical deboning did not alter the nutritional indices.

3. The protein quality and digestibility of the breast were somewhat higher than those for other parts.     

Expression of APOB,ADFP and FATP1 and their correlation with fat deposition in Yunnan’s top six famous chicken breeds

ABSTRACT

1. Adipose differentiation related protein (ADFP), fatty acid transport protein 1 (FATP1) and apolipoprotein B (APOB) are suspected to play an important role in determining intramuscular fat and in overall meat quality.

2. Yunnan’s top six famous chicken breeds (the Daweishan Mini, Yanjin Black-bone, Chahua, Wuding, Wuliangshan Black-bone and Piao chicken) are known for the high quality of their meat, but little is known about their expression of these three genes.

3. The present study aimed to examine the ADFP, FATP1 and APOB genes in different tissues of these six breeds at different development stages. The subcutaneous fat from the back midline and front, abdominal fat, liver and muscle tissue was sampled at 28, 49, 70, 91 and 112 days. The expression of ADFP, FATP1 and APOB was measured by real-time PCR.

4. The results showed that the expression of the three genes differed depending on age, tissue types and breeds. However, the expression of the three genes correlated with fat traits. In conclusion, the expression of the ADFP, FATP1 and APOB genes is associated with the fat traits of Yunnan’s top six chicken breeds. These results could help with molecular marker screening and marker-assisted breeding to improve the quality of poultry for meat production.     

A novel 31-bp indel in the paired box 7 (PAX7) gene is associated with chicken performance traits

1. A novel 31-bp indel polymorphism in intron 3 of the chicken paired box 7 (PAX7) gene was identified and genotyped in an F₂ resource population of Gushi chicken crossed with Anka broiler to analyse its associations with chicken growth, carcass and meat quality traits.

2. Results showed that the 31-bp indel was significantly associated with body weight at 4, 6, 8, 10, 12 weeks of age and body size indices including shank length, shank girth, body slanting length at 8 and 12 weeks of age. Significant associations were found for carcass weight, semi-evisceration weight, evisceration weight, breast muscle fibre diameter, leg muscle fibre diameter, breast muscle fibre density, while no significant association with leg muscle fibre density was observed.

3. It was concluded that the 31-bp indel in intron 3 of the PAX7 gene was associated with chicken growth, carcass and meat quality traits where the 31-bp deletion had a negative effect on chicken growth and carcass traits and positive effect on meat quality traits.     

Effect of chicken meat replacement by spent laying hen meat on physicochemical properties and sensorial characteristics of fresh sausage

1. Sausages were used to assess the effects of chicken meat replacement by spent laying hen meat on the quality parameters and sensorial properties.

2. Five formulations were developed: control (CON) containing 100% chicken meat and 4 levels of chicken meat replacement with spent laying hen meat: 25% (T25), 50% (T50), 75% (T75) and 100% (T100).

3. Appearance, texture, succulence, flavour and overall consumer acceptance were analysed. Parameters such as moisture, ash, fat and protein content, pH, cooking loss and colour parameters (lightness (L*), redness (a*), yellowness (b*)) were analysed, as well as the texture properties (hardness, elasticity, cohesiveness and chewiness).

4. Statistical analysis did not reveal significant (P > 0.05) differences in chemical composition and colour parameters among formulations. On the other hand, CON treatment showed the lowest (P < 0.05) cooking loss (20.45%) that increased as spent laying hen meat increased in the formulation (24.92% vs. 27.65% vs. 28.12% vs. 33.05%, for T25, T50, T75 and T100 batches, respectively).

5. Regarding textural parameters, T75 and T100 formulations presented higher (P < 0.05) hardness and chewiness compared to the other ones.

6. Concerning to sensorial characteristics, the T100 formulation presented the lowest average scores (P < 0.05) for all attributes studied. However, the other batches (T25, T50 and T75) did not show significant differences for appearance, texture, succulence, flavour and overall acceptability attributes compared with the CON formulation.

7. The results indicated that the substitution of up to 75% of chicken meat by spent laying hen meat did not decrease the sensory acceptance of the sausages by consumers, demonstrating that this level of substitution in sausages allows better use of spent laying hen meat.     

Effect of reduced dietary protein and supplementation with a docosahexaenoic acid product on broiler performance and meat quality

1. Chicken breast meat is a lean meat due to its low content of intramuscular fat (IMF) resulting in an overall lower acceptability by consumers due to a decrease in juiciness, flavour and increased chewiness. Recently, studies performed in pigs suggested the possibility of increasing IMF by decreasing dietary crude protein (CP) content, an effect possibly mediated through an increased lipogenesis.

2. Dietary supplementation with lipids rich in omega 3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) may modulate an increase in the content of these fatty acids in meat from monogastric animals and, thus, promote the daily intake of n-3 LC-PUFA by humans.

3. LC-PUFA are very susceptible to oxidation, resulting in off-flavours that affect meat quality and consumers’ acceptability.

4. This trial was conducted to assess the effect of reducing dietary CP, from 21% to 17%, on chicken’s meat IMF content and, simultaneously, to evaluate if a complementary supplementation with a proprietary n-3 LC-PUFA source (DHA Gold?) could improve meat quality. These effects were assessed by measuring productive performance and meat quality, oxidative stability, sensory traits and fatty acid profile.

5. A reduction in CP content of broiler diets, from 21% to 17%, balanced for lysine, improved performance while it was not sufficient to increase IMF content in chicken meat. In contrast, DHA Gold? supplementation had a positive impact both in broiler productive parameters and in meat fatty acid profile.

6. In addition, incorporation of 7.4% of DHA Gold? in the diet promoted carcass yield but negatively affected chicken meat acceptability by consumers, due to a decrease of meat oxidative stability.

7. Overall the data suggest that neither a dietary supplementation with DHA Gold? nor a reduction in CP have a direct positive effect in the levels of IMF present in broiler meat.     

Is it possible to increase n-3 fatty acid content of meat without affecting its technological and/or sensory quality and the growing performance of chickens?

1. The aim of this study was to increase the content of n-3 fatty acids (FA) of meat without affecting its sensory and/or technological properties or the growth performance of chickens reared under standard conditions. Male chickens, Ross 308, were distributed into 5 groups corresponding to 5 different diets for the growing and finishing periods: control (T), containing extruded linseeds exhibiting high concentration of fibre (ELHF), extruded linseeds exhibiting low concentration of fibre (ELLF), microalgae, or an association of 75% ELLF and 25% MA (ELLF+MA).

2. The diet containing microalgae induced a decrease in feed consumption without affecting growth rate. Chickens exhibited a lower feed conversion ratio than the other groups for the growing and finishing periods but also the whole rearing period. The use of linseeds in diets had no effect on the growth performance of chickens in comparison to the control group.

3. The dietary enrichment with n-3 FA had few effects on carcass composition or the ultimate pH and colour of breast meat. The microalgae increased the meat susceptibility to oxidation. The lipid content of breast meat was not affected by the diets. The breast meat of chickens fed on diets containing linseeds and/or microalgae had greater n-3 FA content (2.4 to 3.9 times higher than group T). The linseeds and microalgae mainly increased the contents in linolenic acid and long chain n-3 FA, respectively.

4. Dietary enrichment with n-3 FA had no effect on the sensory quality of fillets whereas the thighs of the MA group exhibited the lowest score for the flavour “chicken” and the greatest score for the flavour “abnormal” corresponding to a fish flavour.

     

Comparative evaluation of carcass traits and meat quality in native Aseel chickens and commercial broilers

1. A comprehensive study was conducted to analyse the meat quality attributes, composition and carcass traits in Aseel chickens and commercial broilers at market age on the basis of physiological age. A total of 20 Aseel (26 and 56 weeks) and 20 broiler (6 weeks) chickens were divided into two groups on a live weight basis, i.e. large (≥2.5 kg) and small (<2.5 kg) with 10 birds in each subgroup.

2. The pH of meat did not show any significant variation between Aseel and broiler chickens. The meat from heavier birds had significantly higher pH. Shear force value and hydroxyproline contents were significantly higher in Aseel chickens. Aseel birds had significantly higher red (a*) colouration and lower lightness (L*) than broiler chickens.

3. The texture and acceptability of Aseel meat were significantly higher.

4. Scanning electron microscopy revealed that muscle fibres in Aseels were arranged in a more coiled pattern making the muscle tough. A larger amount of connective tissue was also observed between the muscle fibres compared with the broiler chickens.

5. The dressing percentage was significantly higher in larger chickens. Commercial broilers recorded significantly higher meat proportion and lower proportion of bone. The meat:bone ratio was 1.07:1.0 in Aseel and 1.31–1.0 in broiler chicken. Breast muscle content was significantly lower in smaller Aseel chickens. Aseel chicken had stronger and heavier backs and shanks. Abdominal fat percentage was significantly lower in Aseel (0.73–0.78%).

6. The study concluded that the firm texture of Aseel meat was due to the high collagen content and interlocking connective tissue between the muscle fibres. The texture and acceptability of Aseel meat was higher. Aseel cocks had strong legs, lean meat and less abdominal fat, making them a high-value meat bird in addition to their aggressive fighting ability.

     

Is it possible to increase the n-3 fatty acid content of eggs without affecting their technological and/or sensorial quality and the laying performance of hens?

1. The aim of this study was to increase the n-3 fatty acid (n-3 FA) content of eggs without affecting their sensorial and/or technological properties or the laying performance of hens. Laying hens from line 477 were divided into 5 groups corresponding to 5 different diets over the laying period: control diet (C) and diets containing extruded linseed with a high level of fibre (ELHF), extruded linseed with a low level of fibre (ELLF), microalgae, or a combination of 75% ELLF and 25% MA (ELLF+MA).

2. Dietary enrichment with n-3 FA had no effect on the laying performance, hen body weight or egg white viscosity. The egg yolks produced by hens fed the diet containing microalgae were redder than egg yolks from the other groups, suggesting the presence of red pigments in the microalgae preparation. However, the colour difference was low and not perceptible to the human eye. Moreover, colour measurement of egg yolks by sensorial analysis panellists using the Roche colour fan did not reveal a diet effect on this parameter.

3. Egg yolk lipid content was not affected by diet. The egg yolk of hens fed on diets containing linseed and/or microalgae had greater n-3 FA content (×2.5 to 2.9 compared to group C). Linseed mainly increased the linolenic acid content (×3.0 to 3.4 compared to group C) and the microalgae increased the LC n-3 FA content (×4.1 compared to group C). Dietary enrichment with n-3 FA had no effect on the sensorial quality of shell cooked eggs except for the “unusual flavour” criterion for which the score was higher for the MA group compared to the other groups and corresponded to a fishy flavour.

     

Influences of end-point heating temperature on the quality attributes of chicken meat

1. This study aimed to evaluate the changes in physicochemical, textural and sensory characteristics of broiler (BR) and Taiwan native chicken (TNC) pectoralis muscle heated at temperatures of 50–95°C.

2. With increasing temperature, cooking loss, collagen solubility, shear force value and hardness, of samples increased in both chicken breeds. Rapid decreases in protein solubility were observed when the meat was heated to 50°C and gradually decreased thereafter.

3. Meat from BRs and native chickens performed differently upon heating in certain characteristics. TNC meat had longer cooking time and lower myofibrillar fragmentation index than BR meat did. TNC meat had higher collagen content, shear force values and springiness but lower collagen solubility than BR meat did.

4. BR meat had significantly higher onset and end transition temperatures than TNC meat did. In BR meat, a sensory analysis revealed that moisture release decreased and chicken flavour increased with increasing temperature.

5. Protein solubility, cooking loss and the texture of heated meat were highly correlated.

6. This study scientifically assessed the performances of the two breeds of chickens with different thermal treatments; producers could utilise the information to produce poultry products with more desirable qualities.

     

Effect of hydrolysed and regular dairy proteins on the texture, colour and microstructure of poultry meat emulsions

1. The effects of 2% whole milk proteins, milk protein's two major components (caseinate and whey) and some of their fractions (beta-lactoglobulin and two hydrolysed whey proteins) were evaluated in a frankfurter-type product made from mechanically deboned chicken meat. 2. Adding caseinate, regular whey protein and the two whey protein hydrolysates (WPH-I and II) significantly reduced cooking loss compared to the control; lowest reduction was obtained with the two hydrolysates. 3. Caseinate and regular whey increased hardness, but WPH-I and II substantially reduced hardness, fracturability and springiness. 4. The more hydrolysed whey (8.5% vs 5.2%; WPH-II vs WPH-I, respectively) caused a greater disruption to texture, which could be explained by the light micrographs showing an interference with meat protein binding. 5. The most cost-effective ingredient tested here was the caseinate.     

Isolation of atypical enteropathogenic Escherichia coli from chicken and chicken-derived products

1. Atypical enteropathogenic Escherichia coli (EPEC) strains from chicken and chicken-derived products were isolated and characterised.

2. The strains presented a wide variety of serotypes, some have been reported in other animal species (O2:H40, O5:H40) and in children with diarrhoea (O8:H-). Most of the strains carried intimin β.

3. The results indicate that chicken and chicken products are important sources of atypical EPEC strains that could be associated with human disease, and highlight the need to improve hygiene practices in chicken slaughtering and meat handling.

     

Manufacture of spent hen ayami and its utilisation in meatloaf and fresh sausage

1. Spent hens were slaughtered, hand deboned and then further processed into a surimi-like material, ayami, which was used to manufacture meatloaf and fresh sausage as value-added products. 2. Yields of deboned muscle and of ayami (% of deboned muscle) were 34.4 to 43.7% and 63.6%, respectively. 3. The ayami composition was: moisture 78.3%, ash 0.28%, fat 3.7%, protein 15.3% and carbohydrate 2.4%. Its pH value ranged from 5.65 to 6.10, and the water-holding capacity from 35.6 to 37.8. 4. Three formulations of meatloaf were prepared with 0, 7.5 and 15% chicken fat and with a blend of herbs and spices. The most acceptable of the three was used for the manufacture of meatloaf and fresh sausage. 5. Microbial testing was conducted on freshly prepared formulation of the meatloaf (15% fat) and sausage, and on frozen stored samples (-18 degrees C, 10 d). All had acceptable microbial quality. 6. Sensory analysis showed that the 15% fat formulation of the meatloaf was the most liked and the fresh sausage was consumer acceptable.     

Effects on chick performance and nutrient digestibility of an endo‐xylanase added to a wheat‐ and rye‐based diet in relation to fat source

1. A study with growing chicks investigated the effects of an inclusion of an endo‐xylanase preparation (LYXASAN®) to a wheat‐ and rye‐based diet on performance and nutrient digestibility in relation to the fat source.

2. The basal diet contained 500 g wheat and 100 g rye/kg of diet. The basal diet was supplemented with either 65 g soya oil/kg or 60 g blended animal fat and 5 g soya oil/kg.

3. Endo‐xylanase added to the soya oil diet did not affect weight gain, but there was a numerical improvement in food conversion efficiency which was not statistically significant. When the endo‐xylanase preparation was added to the blended animal fat diet, both weight gain and food utilisation were improved by 9.5% and 6.0%, respectively (P< 0.05).

4. Digestibilities of organic matter, crude fat, crude fibre and NFE were not significantly affected by adding endo‐xylanase to the soya oil diet. However, when endo‐xylanase was included in the blended animal fat diet, digestibility of organic matter, crude fat, crude fibre and NFE were improved (P<0–05). The improvement in fat digestibility was the most pronounced, amounting to 9–4%. Nitrogen retention and metabolisable energy content were improved significantly by the addition of an endo‐xylanase to the animal fat diet (P< 0.05), by 6.6% and 6.5% respectively.

5. From the results of this study, it can be concluded that the effects on chick performance and nutrient digestibility of a dietary endo‐xylanase in a wheat‐ and rye‐based diet are influenced to a considerable degree by the type of fat in the diet.     

Effect of synbiotic supplementation and dietary fat sources on broiler performance,serum lipids,muscle fatty acid profile and meat quality

1. A 42-d trial was conducted to investigate the effect of adding a synbiotic supplement to diets containing two different types of fat on performance, blood lipids and fatty acid (FA) composition and oxidative stability of breast and thigh meat in broilers.

2. A total of 800 one-d-old male broiler chickens were randomly assigned into 1 of 8 treatments with 4 replicates of 25 birds per treatment. The experiment consisted of a 4 × 2 factorial arrangement of treatments including 4 concentrations of synbiotic (0, 0.5, 1 or 1.5 g/kg diet) and 2 types of fat [sunflower oil (SO) or canola oil (CO)] at an inclusion rate of 50 g/kg diet.

3. Dietary fat type did not affect body weight gain (BWG) or feed conversion ratio (FCR) during the overall experimental period (0–42 d). However, fat type modified serum lipid profile and FA composition and 2-thiobarbituric acid-reactive substances (TBARS) content in breast and thigh meat.

4. The addition of synbiotic to the diet linearly improved overall BWG and FCR and also decreased serum cholesterol and low-density lipoprotein cholesterol concentrations. The TBARS value in thigh meat after 30 d of storage at 4°C was linearly decreased as the synbiotic inclusion concentrations in the diets increased. Dietary synbiotic also decreased the proportion of monounsaturated fatty acids and increased n-6 polyunsaturated fatty acid (PUFA) concentration in thigh meat, whereas the FA profile of breast meat was not affected by synbiotic supplementation. Moreover, the PUFA/SFA ratio in the breast meat was linearly increased when synbiotic was included in the CO-containing diets.

5. In conclusion, the addition of synbiotic to broiler diets had a positive effect on growth performance, blood lipid profile and meat quality. The results also support the use of synbiotic to increase the capacity of canola oil for enhancing PUFA/SFA ratio of breast meat in broilers.

     

Precooked chicken: Effect of cooking methods and batter formula on yields and of storage conditions on 2‐thio‐barbituric acid values

An experiment was conducted to provide information on the development of rancidity in precooked frozen chicken pieces. Emphasis was placed on measuring the effects of storage time, batter formula, cooking of different pieces, 2‐thio‐barbituric acid (TBA) number, yield, moisture and fat content of the frozen product.

Steam cooking of chicken pieces reduced the yield when compared to microwave cooking. This method of precooking decreased the yield of the thigh more than that of the other parts cooked. The breast retained a higher percentage of batter than did either the thigh or drum. This higher yield for the breast continued after final cooking.

By correcting for moisture content, no differences in development of rancidity was observed between the two cooking methods. The thigh‐drum combination was more rancid than the breast. No difference was noted in the development of rancidity for the precooked chicken stored for 6, 8 or 10 months. Breast meat contained less extractable fat, when based on dry sample weight, than did the thigh‐drum meat. Chicken cooked by steam contained more moisture than did those parts cooked by microwave.     

Physical and chemical properties of meat from scavenging chickens and helmeted guinea fowls in response to age and sex

1. The effects of age and sex on body weight, carcass traits, physical and chemical properties of breast muscle from chickens and helmeted guinea fowls managed under village free-range conditions were assessed in random samples of 48 guinea fowls and 48 chickens obtained from local markets.

2. Guinea fowls had higher body weight, hot carcass weight, cold dressed weight and breast weight than chickens.

3. Guinea fowls had more dry matter, protein and less fat than chickens. Ash content did not differ between guinea fowls and chickens. Protein and fat increased, whereas dry matter and ash decreased with age (P < 0.05)

4. Chicken meat was lighter, less red and more yellow than guinea fowl meat. Cooking loss was higher in guinea fowls, male and grower birds than chickens, females and adult birds, respectively. Shear force was affected by age, as mature birds had a higher value than growers.

5. Guinea fowl carcasses contained more meat that was leaner, higher in protein and redder compared with chicken meat. As age increased the meat increased in protein and fat content and shear force, whereas colour became darker, redder and yellower.     

Variation in the chicken LPIN2 gene and association with performance traits

1. The objective of the study was to investigate the distribution of LPIN2 variants and haplotypes among breeds and perform an association analysis of the variants and haplotypes with the broiler traits in chickens.

2. Six breeds were used to study the variation and distribution of chicken LPIN2, and an F₂ resource population was used to measure growth traits, carcass traits, meat quality traits and serum biochemistry parameters.

3. A c.-599G>A variant was located in the promoter region of LPIN2 and c.444G>A and c.1730A>T (E577D) coding variant mutations were detected. Linkage disequilibrium tests showed that these three variants were under moderate linkage disequilibrium in the 6 breeds and 7 haplotypes were constructed. The distribution of variation/haplotypes presented clear differences among breeds.

4. Association analysis showed that c.-599G>A was associated with leg muscle weight, jejunum length, ileum length, leg muscle fibre density and leg muscle fibre diameter; c.444G>A was associated with spleen weight, ileum length, body weight at hatch and metatarsus length at 8 weeks; c.1730T>A had significant effects on chicken liver weight, heart weight, body weight at 10 weeks, serum albumin and glucose.

5. Diplotypes were significantly associated with body weight at hatch, heart weight, pancreas weight, duodenum length, leg muscle fibre density and lactate dehydrogenase.

     

Texture and acceptability of goat meat frankfurters processed with 3 different sources of fat

The objective of this research was to evaluate the texture and consumer acceptability of goat meat frankfurter formulations with no added fat (NAF), beef fat (BF), or canola oil (CO). Consumer sensory evaluation, fat, and moisture and texture profile analyses were performed on goat meat frankfurters produced with the fat sources BF, CO, and NAF. For sensory evaluations, NAF was less tender (P = 0.007; 4.90 vs. 4.11 and 4.35 for BF and CO, respectively) and the flavor was liked less (P = 0.004; 4.59 vs. 3.83 and 4.30 for BF and CO, respectively); BF was scored as the juiciest (P = 0.003; 3.86 vs. 4.49 and 4.58 for CO and NAF, respectively); and CO had the least amount of flavor (P = 0.029; 3.65 vs. 3.12 and 3.10 for BF and NAF, respectively). Moisture was least (P < 0.001) in CO (46.59%), followed by BF (48.57%) and NAF (55.80%). The amount of fat was not different (P = 0.761) in BF (24.36%) or CO (24.43%) but was less (P < 0.001) in NAF (9.06%), as expected. The NAF had the most protein (P < 0.001; 34.14%), followed by CO (27.98%) and BF (26.07%). For texture profile analyses, NAF had the least hardness value (P = 0.008; 3.92 vs. 4.48 and 4.40 for BF and CO, respectively) and least chewiness value (P = 0.026; 2.89 vs. 3.39 and 3.29 for BF and CO, respectively). Beef fat and CO were not different for hardness (P = 0.596) or chewiness (P = 0.530). No differences were observed in springiness (P = 0.954) or resilience (P = 0.561). The sensory panelists tended to prefer BF for overall acceptability. Results from these data revealed that value-added goat meat products received acceptable sensory scores; therefore, continued research and development will greatly expand the knowledge of goat meat and increase the acceptance of value-added products.