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Health conscious meat consumers prefer low fat meat products due to increasing incidents of high fat induced diseases. Manufacturing meat products with fat replacers (FR) enable to reduce fat and to alleviate the problems with the reduction of fat in products. Therefore, the present study was undertaken with the objectives of developing a palatable and economic formulary for low fat beef burger (LFBB) with carrageenan (CG), tapioca starch (TS), pregelatinised pork skin collagen (PSC) and their blends as FR and to assess its pH, cooking characteristics, proximate composition, nutritional value, textural and organoleptic qualities and shelf life under aerobic (AP) and vacuum packaging (VP) at 0-4oC and -20oC and its cost of production. Beef burgers (BB) are formulated at two different fat levels, viz., full fat (FF) 20 per cent and low fat (LF) 5 per cent as controls. Seven formulations of LFBB with 5 per cent fat are prepared with 0.5 per cent CG, 1.5 per cent TS, 2 per cent PSC and their blends, viz., CG-TS - 0.5% CG & 1.5% TS; CG-PSC - 0.5% CG & 2.0% PSC; TS-PSC - 1.5% TS & 2.0% PSC; CG-TS-PSC - 0.5% CG, 1.5% TS & 2.0% PSC as FR.

BB are prepared as per the formularies with minced lean beef trimmings, tallow, salt, spices and condiments, rusk, ice flakes and FR. They are packaged aerobically in HDPE and in vacuum in polyethylene-polyamide (PEPA) pouches. pH, cook yield (CY), cook loss (CL), fat retention percentage (FRP), moisture retention percentage (MRP), dimensional shrinkage (DS), water holding capacity (WHC), Warner-Bratzler Shear Force (WBSF), Hunter L*, a*, b* colour values, proximate and mineral composition and nutritional value, purge loss (PL), Thiobarbituric Acid Reactive Substances (TBARS) value and sensory qualities are assessed on d 0, 10, 20 and 30 of storage at 0-4oC and -20oC or till spoilage, whichever is earlier. Six trials of the experiment were conducted.

Cooking reduced the acidity of all the burgers. By the addition of FR a significantly (P< 0.05) very low acid cooked LFBB could be prepared. CY of burgers with CG-TS-PSC was significantly (P< 0.05) the highest with 85.84 per cent. LFBB with blends of FR significantly (P< 0.05) increased CY and correspondingly reduced CL. The DS in LFBB with CG-TS-PSC was significantly (P< 0.05) the lowest with 13.21 per cent. Addition of blends of FR holds water and fat in LFBB and reduces DS during cooking. FRP and MRP in CG-TS-PSC formulation was significantly (P< 0.05) the highest with 97.66 and 74.36 per cent, respectively due to blends of CG, TS and PSC.

The WHC of LFBB with CG-TS-PSC was 95.36 per cent and WBSF value 5.30 N comparable to FF and the burgers were significantly (P< 0.05) most succulent, juicy and tender with the addition of blends of FR compared to tougher BB without FR. According to Hunter L*, a*, b* values, LFBB with blends of FR, especially CG-TS-PSC was lighter, less reddish (more bluish) and less yellowish (more greenish) and comparable to FF burger.

Fat content in the beef trimmings and PSC were < 1.76 per cent. Cooking significantly (P< 0.05) reduced moisture content with a corresponding increase in the protein, fat, carbohydrate and ash. The percentage total calorific value of LFBB ranged from 6.36 to 7.18 of the Recommended Dietary Allowance (RDA). The contribution of fat to RDA of calorific value was from 2.22 to 2.42 per cent only, which was below the recommended 30 per cent. More than one third of the daily requirement of protein is obtained from 100g of LFBB. LFBB with FR are good sources of Na, K and P but not of Ca.

Blends of FR in LFBB, especially CG-TS-PSC, were more efficient in significantly (P< 0.05) reducing PL and TBARS value on storage at 0-4oC for 10 days and at -20oC for 30 days in AP and VP. TBARS values were lower than the acceptable range of 1mg malonaldehyde/kg for oxidative rancidity. The low fat content and the presence of onion containing antioxidants in the formulary would have synergistically acted with CG in reducing the TBARS.
On sensory evaluation on zero day, the LFBB with CG-TS-PSC scored significantly higher (P< 0.05) values of 7.00 and above for very good appearance and colour, very intense flavour, very desirable texture, juiciness, practically nil mouth coating and very acceptable overall acceptability similar to FF burger. But saltiness was very desirable than in FF. The LFBB with CG-TS-PSC in AP and VP retained all the sensory attributes and proximate composition even on storage. The very acceptable nature of CG-TS-PSC formulation might be due to the synergistic effect of fat replacers.

The LFBB with 5 per cent fat and CG (0.5%), TS (1.5%), PSC (2%) and their blends as FR are developed economically with very acceptable overall acceptability, CY, nutritional quality, reduced PL and oxidative rancidity and shelf life up to 10 days at 0-4oC and 30 days at -20oC under AP and VP. The best LFBB with overall acceptability was CG-TS-PSC followed by CG-TS, CG-PSC, TS-PSC, PSC, CG and TS. Blends of FR are better than single FR, particularly CG-TS-PSC, as they increased CY, FRP, MRP, WHC, sensory attributes and decreased pH, CL, DS, WBSF, PL and TBARS. Further investigations with production of large quantities are required for calculation of cost of production at commercial scale.