A study was conducted to improve dietary fibre content of chicken nuggets by incorporating corn bran (CB), dried carrot pomace (DCP) and dried tomato pomace (DTP) as dietary fibre sources. Lean meat was replaced with each dietary fibre source at 3%, 6% and 9% level. One product from each fibre source was selected on the basis of sensory evaluation. Sensory acceptability of 3% fibre treated nuggets was comparable with control and further increase in fibre level resulted in a decline in sensory acceptability. All CB and DCP treated nuggets were harder and firmer than control while 3% DTP treated nuggets were harder than control. Fibre addition resulted in less springier and less cohesive nuggets. Yellowness increased in DCP added nuggets while both redness and yellowness increased in DTP added nuggets. Fibre treated nuggets had less moisture and cholesterol content and higher protein, ash, crude fibre, emulsion stability and cooking yield. pH of DCP and DTP treated nuggets was lower than control. Drastic increase in total dietary fibre and insoluble dietary fibre content was observed in treated nuggets. Sensory scores of nuggets declined significantly while thiobarbituric acid reacting substance value (TBARS) and microbial counts increased significantly during refrigerated storage. It is concluded that incorporation of dietary fibre at 6% level resulted in healthier and fibre enriched nuggets with higher cooking yield and acceptability upto 15th day of refrigerated storage.
Recent epidemiological investigations have recognized the association of eating of meat products with prevalence of broad range of emerging diseases such as obesity, heart related diseases, cancer and various other disorders (Virtanen
Codex Alimentarius Commission defined dietary fibre as the carbohydrate polymers with three or more than three monomers, which are not digested or absorbed in the human small intestine (Codex Alimentarius Commission, 2019). Addition of dietary fibre in the diet reduces the occurrence of cardiovascular disease, diabetes and certain types of cancer (The Lancet, 2019). Moreover, source of dietary fibres are common agricultural byproducts that are relatively low priced and their addition in meat may reduce overall production cost of meat products. The recommended intake of dietary fibre is 28-36 g/day for adults, of which 70-80% should be insoluble fibre (Mehta
The cereal brans have appreciable quantity of insoluble fibre, minerals, lipids, vitamins and pigments (Alan
Fruit and vegetable byproducts are a plentiful source of nutrients including dietary fibre and phytochemicals and can be utilized as new and cost effective sources of healthy and functional ingredients. Lycopene which is a proven cancer fighting phytochemical is the most abundant carotenoid present in tomato especially in its peel (OShea
Chicken nugget is a ready to eat convenience product requiring short preparation time. The product is popular among consumers due to high nutritional value and better organoleptic quality. Keeping above points in view, this study was carried to develop dietary fibre enriched chicken nuggets by incorporating corn bran (CB), dried carrot pomace (DCP) and dried tomato pomace (DTP) and study their effect on nutritional, physico-chemical and sensory quality of developed products.
Corn bran was procured from Vitarich agro food (India) Ltd., Kolkata. Carrot and tomato were procured from nearby market. Pomace of carrot and tomato were obtained after extraction of juice. Before extracting juice, tomatoes were blanched in hot water at 70°C for 2 minutes. Both types of pomace were separately dried. All the three fibre sources were ground, packaged in air tight container and stored under frozen conditions for further use.
Deboned chicken meat was minced in an electrical mincer (4 mm plate). Control nuggets were prepared by adding sodium chloride (1.6 g), sodium tripolyphosphate (STPP) (0.3 g), sodium nitrite (0.015 g), spice mix (1.9 g), condiments paste (3 g), refined wheat flour (2 g), water (8 g), groundnut oil (8 g) and egg albumen (10 g) to minced meat (65.2 g).
Treated chicken nuggets were prepared by incorporating CB, DCP and DTP each at three different levels individually viz. 3, 6 and 9% by replacing lean meat. Other ingredients were used in similar concentration as in control. Minced meat along with additives and dietary fibre sources were mixed in a bowl chopper for 4 - 6 min to prepare a stable emulsion. Raw emulsion was packed in rectangular moulds and cooked in electric oven (165°C for 40 min). Cooked emulsion was cooled to room temperature. Nuggets were prepared by cutting cooked emulsion to 2-3 cm3 size. They were packaged in polythene bags and stored at refrigerated temperature for further analysis.
Proximate composition (moisture, fat, protein, ash and crude fibre content) (AOAC, 1995), pH (Trout
A combination of enzymatic and gravimetric method (AOAC, 1997) by utilizing TDF assay kit (Sigma-Aldrich Inc.) was used for estimating soluble dietary fibre (SDF), insoluble dietary fibre (IDF) and total dietary fibre (TDF) content.
The total lipids from a sample were extracted as per the method of Angelo
The analysis of texture profile of chicken nuggets was performed as per the procedure outlined by Bourne (1978) using TAHD Plus Texture Analyser (Stable Micro Systems, England). A compression platform of 70 mm diameter was used as a probe. Samples (20 mm cube size) were compressed to 50% of their original height. A time interval of 5 s was allowed between two compression cycles. Force time deformation curves were obtained with a 50 kg load cell applied at a cross head speed of 2 mm/s.
Force required to shear a nugget sample of 1 cm3 size was measured using warner bratzler shear probe of texture analyser and expressed in Newton (N).
CIE Lab, L* (lightness), a* (redness) and b* (yellowness) of cooked products were measured using a chroma meter (Konica Minolta Sensing, Inc., Japan) with 8 mm orifice for measurement. The equipment was standardized with a white standard plate before measurement.
Chicken nuggets were evaluated for their sensory quality by a semi trained panel consisting of members from the faculty and research fellows of the department. Sensory characteristics i.e. colour and appearance, flavour, texture, tenderness, juiciness and overall acceptability (OAA) were analyzed using 8-point descriptive scale where score 8 and 1 indicated extremely desirable and extremely undesirable respectively.
Standard plate count (SPC), psychrotrophic count (PC) and yeast and mold counts of chicken nuggets were estimated during refrigerated storage (APHA, 1984).
The data acquired were evaluated by analysis of variance (ANOVA). One way ANOVA for fresh products and two way ANOVA for refrigerated stored products was performed. To find out the significant differences in means, Duncan’s multiple range test was used.
Colour and appearance scores of all CB and DCP treated nuggets and DCPN-1 nuggets incorporated with 3% tomato pomace were similar to control (
No significant difference was noticed in flavour, texture, juiciness, tenderness and overall acceptability scores of control and treatment CBN-1, DCPN-1 and DTPN-1 containing 3% CB, 3% DCP and 3% DTP respectively. Flavour, texture, tenderness and overall acceptability scores of CBN-2 containing 6% CB were significantly lower in comparison to control. Flavour, juiciness and overall acceptability scores of treatment DCPN-2 and flavour scores of treatment DTPN-2 were also significantly lower in comparison to control. However, overall acceptability scores of treatments CBN-2, DCPN-2 and DTPN-2 were around 7.0 meaning very good acceptability. Except for colour scores, treatments CBN-3, DCPN-3 and DTPN-3 had significantly lower scores for all other sensory attributes in comparison to control. Decrease in flavour scores at higher level of dietary fibre incorporation might be due to dilution of meaty flavour. Fibre rich ingredients may have their own characteristics flavour attributes like sourness, bitterness which affect the flavour of meat products. Goncalves
CBN-1, CBN-2, CBN-3= chicken nuggets incorporated with 3%, 6% and 9% corn bran respectively; DCPN-1, DCPN-2, DCPN-3= chicken nuggets incorporated with 3%, 6% and 9% dried carrot pomace respectively; DTPN-1, DTPN-2, DTPN-3= chicken nuggets incorporated with 3%, 6% and 9% dried tomato pomace respectively; Means with different superscripts within a column for a particular fibre treatment differ significantly (p≤0.05).
Hardness scores of CB, DCP and DTP treated nuggets showed a variable trend (
CBN-1, CBN-2, CBN-3= chicken nuggets incorporated with 3%, 6% and 9% corn bran respectively; DCPN-1, DCPN-2, DCPN-3= chicken nuggets incorporated with 3%, 6% and 9% dried carrot pomace respectively; DTPN-1, DTPN-2, DTPN-3= chicken nuggets incorporated with 3%, 6% and 9% dried tomato pomace respectively; Means with different superscripts within a column for a particular fibre treatment differ significantly (p≤0.05).
Gumminess and chewiness scores were significantly lower in all CB treated nuggets. Scores of gumminess and chewiness depend on the scores of hardness, cohesiveness and springiness. Lower springiness and cohesiveness scores in CB treatments contributed to their lower gumminess and chewiness values. In DCP treated nuggets, gumminess and chewiness scores of DCPN-2 were significantly highest and DCPN-3 significantly lowest among all treatments. Highest hardness scores of DCPN-2 contributed to its highest gumminess and chewiness scores. Lowest springiness and cohesiveness scores and lower hardness in comparison to control and DCPN-2 treatments contributed to lowest gumminess and chewiness scores of DCPN-3 nuggets. DTPN-2 and DTPN-3 had significantly lower gumminess and chewiness than control. Firmness scores of all CB and DCP treated nuggets were significantly higher than control while firmness scores of DTP treated nuggets were similar to control.
No significant difference was noticed in lightness, redness and yellowness values of control and CB treated chicken nuggets. Lightness and redness values of DCP treated nuggets were statistically similar to control. Yellowness scores of nuggets increased with increase in DCP and treatment DCPN-3 had significantly higher yellowness scores in comparison to control. A significant increase in redness and yellowness was noticed in DTP nuggets. Dietary fibres influence colour of meat products by virtue of their inherent colour and characteristics. Increase in yellowness might be due to presence of anthocyanins and carotenoids (Goncalves
Treatments CBN-2, DCPN-2 and DTPN-2 containing 6% CB, 6% DCP and 6% DTP were selected for further study on the basis of sensory evaluation. There was a significant decrease in moisture content in fibre enriched nuggets in comparison to control (
Moisture, protein, fat, ash and crude fibre content of CB was 11.62, 10.81, 6.08, 2.14 and 16.64 respectively. Corresponding values for DCP and DTP were 5.09, 6.47, 2.26, 5.98 and 12.93 and 7.54, 15.15, 4.38, 4.08 and 27.33 respectively; CBN-2, DCPN-2 and DTPN-2: Chicken nuggets incorporated with 6% corn bran, 6% dried carrot pomace and 6% dried tomato pomace respectively; Means with different superscripts within a row differ significantly (p≤0.05).
Significant and drastic increase in TDF and IDF content of treated nuggets was observed. This was obvious due to higher amount of fibre content in dietary fibre ingredients. SDF content of treatments DCPN-2 and DTPN-2 was also significantly higher than control. Treatment DCPN-2 had significantly highest TDF, SDF and IDF which was due to significantly highest TDF, SDF and IDF content in DCP. Comparatively, the increase in TDF and IDF content was more appreciable than increase in SDF. This was also due to nature of dietary fibre present in materials used. Tomato fibre contained more amount of insoluble fraction in comparison to soluble fraction (Ratio 10:1) and its fibre type resembled more with cereals (Garcia
Colour and appearance scores of treatment DTPN-2 were significantly higher than all other treatments during entire storage period (
CBN-2, DCPN-2 and DTPN-2: Chicken nuggets incorporated with 6% corn bran, 6% dried carrot pomace and 6% dried tomato pomace respectively; Means with different small superscripts within a column and capital superscripts within a row for a particular parameter differ significantly (p≤0.05).
Flavour scores of control nuggets were significantly higher than fibre enriched nuggets on 0 day. Flavour scores of all the nuggets decreased significantly during storage. At the end of storage period of 15 days, favour scores of DCPN-2 and DTPN-2 nuggets were statistically similar to control. The results indicate that DCP and DTP incorporation resulted in a positive effect on favour scores of nuggets during refrigerated storage. Flavour scores of both control and fibre enriched nuggets were above 6.0 at the end of refrigerated storage indicating more than moderate acceptability.
Texture and tenderness scores of control and treatments DCPN-2 and DTPN-2 were comparable on 0 day as well as during storage. Texture and tenderness scores of treatment CBN-2 were significantly lower than control on all days of storage. The scores for texture and tenderness decreased significantly in both control and treated nuggets during storage but the scores were well within the acceptability limits at the end of storage. Juiciness scores of treated nuggets were significantly lower than control nuggets on 0 day. Juiciness scores declined significantly in all the treatments during storage. From 5th day onwards, juiciness scores of DCPN-2 and DTPN-2 were comparable with control till the end of storage period. Results indicate that carrot pomace and tomato pomace were able to retain meat juices in a better way. Overall acceptability scores of fresh control nuggets were significantly higher than fresh treated nuggets. The OAA scores of control and treated nuggets declined significantly during storage. However, OAA scores of DCPN-2 and DTPN-2 treatments were comparable with control on 15th day of storage.
No significant difference was noticed in TBARS value of control and treated nuggets on 0 day. Significant increase in TBARS value of control and treated nuggets was noticed with increase in storage period. However, the rate of increase was less in DCP and DTP treated nuggets resulting in significantly lower TBARS value of DCPN-2 and DTPN-2 treatments in comparison to control on 20thday of storage. Bioactive compounds in pomace might have contributed to antioxidant effect.
No significant difference was noticed in any of the microbial counts between control and treated nuggets on 0 day as well as during storage (
CBN-2, DCPN-2 and DTPN-2: Chicken nuggets incorporated with 6% corn bran, 6% dried carrot pomace and 6% dried tomato pomace respectively; Means with different small superscripts within a column and capital superscripts within a row for a particular parameter differ significantly (p≤0.05).
Healthier chicken nuggets with better cooking yield and enriched with dietary fibre can be prepared by replacing chicken meat with 6 % corn bran, 6 % dried apple pomace and 6 % dried carrot pomace individually. 100 g serving of each type of fibre enriched nugget can meet about 15% of daily requirement of dietary fibre.
Financial assistance provided by Ministry of Food Processing Industries, New Delhi, India is thankfully acknowledged.