Effect of Curing, Antioxidant Treatment, and Smoking of Buffalo Meat on pH, Total Plate Count, Sensory Characteristics, and Shelf Life During Refrigerated Storage

Abstract

The effects of curing, antioxidants, and smoking on pH, total plate count (TPC), and sensory characteristics of buffalo meat stored at 0°C and packed in low density polyethylene (LDPE) bags were investigated. It was observed that treatment of curing, antioxidants (Sodium ascorbate, SA), and smoking, either alone or in combination, significantly (p < 0.05) increased pH and reduced TPC of control meat sample. The combined treatments of curing + smoking and curing + SA + smoking were significantly (p < 0.05) different from the single treatments of curing and smoking (least significant difference, LSD, was found to be less than the difference of log TPC/g values of these treatments). Sensory characteristics, like color and texture, were also significantly improved by single as well as combined treatments of curing, antioxidants, and smoking. However, these treatments did not significantly (p < 0.05) affect aroma of the controlled meat sample. Storage study (at refrigeration temperature, 0°C) revealed that the combined treatment of curing + SA + smoking was found to be significantly (p < 0.05) different and most effective in increasing the shelf life of the controlled meat sample. The shelf lives of meat samples were exactly determined by TPC value and sensory characteristics (total plate count in the order of 10⁷, slimy texture, and undesirable aroma described the beginning of spoilage). The shelf life of control, cured, curing + SA, smoked, cured + smoked, and cured + SA + smoked were found to be 20, 30, 35, 25, 30, and 50 days respectively.

Keywords:

• Curing
• Antioxidant
• Smoking
• Total plate count
• Sensory characteristics
• Shelf life

Introduction

Meat is a highly perishable food product, which has been consumed since time immemorial. Curing, smoking, and salting are the earliest known methods of meat preservation. Nitrites and nitrates for curing was used to develop color in meat. The process of curing was also later adapted as a means of preservation. Curing reduced the in bacterial load vis-à-vis the bacterial conversion of nitrate to nitrite in color fixation.[1] Carefully planned experiments have conclusively shown that sodium nitrate up to 200 ppm could be added to the common salt cured products to hasten the curing process.[2] Sugar, ascorbic acid, and sodium erythorbate have also been used in curing. Contribution to flavor had been reported in cured ham, smoked, and nonsmoked frankfurters.[3]

Smoking is also one of the earliest known methods of meat preservation. The smoking develops many desirable properties: (1) drying effect, (2) desirable organoleptic properties, (3) color enhancement of cured meat, (4) imparting antioxidants to the meat fat, (5) impregnating the outside portion of the meat with constituents of smoke that serve as antiseptics and germicides, (6) an adjuvant action of constituents of the smoke and heat if the process is carried out at a temperature above 49°C, (7) diminution of nitrite content, probably as a result of an aliphatic diazo reaction of protein which occurs at higher temperature, and (8) imparting of a desirable finish or gloss on both the skin and flesh of meat through the agency of aldehyde and phenol condensed resins from the smoke.[4]

Vitamin C and sodium ascorbate were used as natural antioxidants to stabilize the meat color by way of preslaughtering injection in beef.[5] Vitamin C incorporation maintained good color in ground beef up to 5 days under refrigerated conditions when added at a concentration of 500 ppm.[6] Round buffalo meat containing 500 ppm sodium ascorbate had significantly higher color scores, Lovibond tintometer red color units, and lower metmyoglobin content as compared to other levels of sodium ascorbate. The metmyoglobin was positively correlated with thio-barbituric acid reacting substances (TBARS) number.[7] [8]

Most of the research work has been reported on curing and antioxidant treatments, but there is scanty work on either smoking or combination of curing and smoking/curing, smoking, and antioxidants. The objective of the present work was to study and compare the individual and combined effects of curing, smoking, and antioxidants on the quality and shelf life of buffalo meat.

Materials and Methods

Buffalo meat samples were collected from a local meat shop. The animals (male calves, aged 2, 2.5, and 3 years) were slaughtered by the traditional halal method at the slaughter house of Aligarh Municipal Corporation. The animals were given rest (24 h) in a liarage before slaughtering. Meat samples for experimentation were chosen from all three groups including mostly semi-membranosus, semi-tendinosus, and biceps femoris muscles. The samples were procured after 3 h of slaughtering and immediately packed and brought to the laboratory within 5 min and kept at 2 ± 1°C.

Treatment of Raw Meat

Curing

Meat samples were cut into cubes 2.5 × 2.5 × 2.5 cm and were submerged in a curing solution containing 80 g sodium chloride (iodine free), 20 g sugar, 1.16 g of sodium nitrate, and 540 mL of distilled water as suggested by Khordylas.[9] The sample was kept in curing solution for 48 h at 4°C in an ultra low temperature cabinet (Yorco model). Samples were then finally packed in LDPE bags.

Curing and Antioxidant Treatment

The curing solution was prepared as described earlier. It was added with 500 ppm of sodium ascorbate and treated for 48 h at 4°C and finally packed is LDDE bags.

Smoking

Raw, cured, and cured plus antioxidant treated meat samples were smoked in a drum smoke house. Hardwood was used for the generation of smoke. The temperature of smoke was maintained between 50 and 60°C by controlling air draught. The raw buffalo meat was smoked until it developed the properties of smoked meat (smoked meat flavor, partial dehydration of meat, development of a cherry red color, and a glossy surface finish). It took 8 h to develop these desirable characteristics in raw meat whereas cured and cured plus antioxidant treated samples took 9 h for complete smoking.

Determination of Properties

pH

The pH of the meat samples was determined with a digital pH meter (Metzer model). The electrode of the pH meter was calibrated with the help of two buffer solutions of known pH, 4 and 7. One gram of finely ground sample was taken and blended in 10 mL of distilled water in a test tube in a cyclo mixer (Yorco model). The extract was filtered through whattman No. 1 filter paper. The electrode of the pH meter was dipped in the filtrate, and the digital device recorded the pH of the sample.

The ultimate pH of meat and its quality depend upon how the animals were handled before slaughtering. The animals were kept in liarage and given rest for 24 h before slaughtering. This led to the accumulation of glycogen, the only carbohydrate source in animals. When animals are slaughtered, oxygen carrying blood supply is cut off with the stoppage of circulation. The muscles become anaerobic and can no longer maintain the level of ATP by oxidation phosphorylation. The level of ATP is first maintained by conversion of ADP to ATP at the expense of creatin phosphate, but when the latter is exhausted or nearly exhausted, the ATP level falls. Loss of ATP alone triggers anaerobic conversion of glycogen to lactic acid, causing a drop in pH.

Total plate count

Total plate counts for all meat samples were assessed by a direct plate count using serial dilution, spread plate technique with a nutrient agar medium as described by Cappuccino and Sherman.[10]

Sensory Characteristics

Sensory attributes such as color, flavor, texture, and over all acceptability of controlled and treated meat samples, were evaluated by a method recommended by Ranganna,[11] hedonic rating test. A trained panel, consisting of 20 expert judges, was asked to rate the acceptability of the meat samples on a 9-point hedonic scale with a range from “Excellent” to “Extremely Poor.” To analyze the results, numerical values were assigned to each point: 9 = like extremely, 8 = like very much, 7 = like moderately, 6 = like slightly, 5 = neither like nor dislike, 4 = dislike slightly, 3 = dislike moderately, 2 = dislike very much, and 1 = dislike extremely.

A threshold test was conducted for each of the panelists. Threshold tests that measures the ability of an individual to smell, taste, or feel specific characteristics in food or beverages or pure substances are used frequently in selecting panelists for evaluations in product research and development. Also they are used to establish instantly the sensory response of food or food components.

The threshold test defines a statistically determined point on the stimulus scale at which a transition in a series of sensation or judgment occurs. There are mainly three types of thresholds:

a.	Stimulus/detection threshold is that magnitude of stimulus at which transition occurs from no sensation to sensation.
b.	Recognition/identification threshold is the minimum concentration at which stimulus is correctly identified.
c.	Terminal/saturation threshold is the magnitude of a stimulus above which there is no increase in the perceived intensity of the stimulus.

Other sensory evaluation methods include difference test, paired comparison, triangle test, monadic test, multiple sample difference test, numerical scoring test, and composite scoring test. However, it is not possible to discuss every method.

The requirements for panel membership are good health, average sensitivity, high degree of personnel integrity, intellectual curiosity and interest in sensory evaluation, ability to concentrate and learn, and availability and willingness to spend time in evaluation and submission to periodic testing of acuity and consistency. Candidates possessing these qualities are indexed by age, sex, specific likes and dislikes, etc. Laboratory panels are then carefully trained for a specific product. These tests aim to find differences in specific qualities of characteristics between different stimuli and also the direction and/or intensity of the differences. Periodically, the panel is given refresher training.

Color attributes can be judged by the eye. Judging also includes size, shape, uniformity, maturity, and absence of defects. Odor, a vastly complex sensation, is the most important factor in flavor. Flavor embraces the sense of taste, smell, and feeling. As far as human beings are concerned, it is generally agreed that the sense of taste is limited to sweet, sour, salty, and bitter only. The dimensions of these tastes could be estimated chemically. However, their optima in relation to consumer preferences, especially when they occur in combination in a complex food, are not fully understood. For example, there are large numbers of food items having a sweet taste. However, consumers affinity for sweetness differs from one person to another.

Texture is the property of food that is associated with the sense of feel or touch experienced by a finger or the mouth. A textural attribute is best indicated by the sensation caused by contact with hard and soft parts of the mouth.

Statistical Analysis

Data collected on different characteristics were analyzed with the help of a factorial design (9 replications × 6 treatments × 6 storage) by the method suggested by Dospekhov.[12] Each value is a mean of nine observations.

Results and Discussion

Effect on pH

The results of the studies conducted on the effects of curing, smoking, antioxidant treatment, and their combined effects on pH, total plate count, and sensory properties of buffalo meat have been presented in Tables 1–4. The properties were evaluated before and during refrigerated storage (0°C). It was observed that curing had a significant (p < 0.05) effect on the pH of controlled meat. The over all effect of the treatments was found to be significant (p < 0.05) (Table 1). Effects of either individual or combined treatments of curing, antioxidant, and smoking did not differ significantly (p < 0.05) (difference between the pH values was found to be less than least square difference, Table 1). Decrease in pH is indicative of improvement in the meat quality, e.g., water holding capacity, texture, and prevention in drip losses. Ground buffalo meat containing sodium ascorbate (500 ppm) had significantly lower pH and lower cooking loss as compared to control and other levels of sodium ascorbate.[13] ANOVA results depicted that effects of replications on pH were also found to be significant (p < 0.05). Smoking showed cherry red color in controlled meat while the color of cured meat was further enhanced by smoking. The detailed results will be discussed under the sensory properties. The maximum pH value was found in the sample having combined treatment of curing, antioxidant, and smoking (pH value was found to be 6.72 as compared to 5.89 for controlled meat). Curing and smoking caused an increased pH in meat samples due to polyanion formation and an increase the strength of the solution.

Table 1 Effect of curing, antioxidant treatment, and smoking on pH of buffalo meat during refrigerated storage (0 ± 1°C)*

Storage period (days)
Treatments	0	5	10	15	20	25	30	35	40	45	50	55	60	70	80
Samples packed in LDPE bags	pH*
Control	5.89^a ± 0.21	6.00 ± 0.18	5.79 ± 0.19	5.55 ± 0.23	5.26 ± 0.14	5.10 ± 0.26
Cured	6.05^b ± 0.23	6.25 ± 0.25	6.15 ± 0.27	5.95 ± 0.18	5.86 ± 0.15	5.72 ± 0.34	5.65 ± 0.29	5.50 ± 0.31	5.29 ± 0.38	5.11 ± 0.27
Cured + SA treated	5.92^b ± 0.33	6.14 ± 0.28	6.00 ± 0.31	5.86 ± 0.29	5.72 ± 0.31	5.64 ± 0.32	5.56 ± 0.28	5.45 ± 0.36	5.38 ± 0.018	5.29 ± 0.018	5.17 ± 0.018
Smoked	6.25^b ± 0.23	6.17 ± 0.31	5.99 ± 0.43	5.81 ± 0.37	5.69 ± 0.29	5.55 ± 0.35	5.42 ± 0.39	5.39 ± 0.28	5.24 ± 0.31
Cured + smoked	6.30^b ± 0.27	6.30 ± 0.33	6.30 ± 0.17	6.30 ± 0.19	6.23 ± 0.26	6.12 ± 0.23	6.03 ± 0.31	5.90 ± 0.18	5.74 ± 0.23	5.54 ± 0.24	5.43 ± 0.27	5.37 ± 0.19
Cured + SA treated + smoked	6.72^b ± 0.17	6.72 ± 0.23	6.69 ± 0.25	6.54 ± 0.31	6.42 ± 0.018	6.29 ± 0.33	6.15 ± 0.26	6.00 ± 0.19	5.83 ± 0.27	5.65 ± 0.34	5.52 ± 0.31	5.49 ± 0.28	5.34 ± 0.22	5.26 ± 0.25

*Values are the means ± SD of nine observations.

LDPE—Low density polyethylene, SA—sodium ascorbate.

Mean values with different superscript differ significantly (p < 0.05).

Table 2 Effect of curing, antioxidant treatment, and smoking on total plate count (TPC) of buffalo meat during refrigerated storage (0 ± 1°C)*

Storage period (days)
Treatments	0	5	10	15	20	25	30	35	40	45	50	55	60	70	80
Samples packed in LDPE bags	Log TPC/g*
Control	4.30^a + 0.27	5.17 ± 0.34	5.54 ± 0.29	6.84 ± 0.31	7.34 ± 0.37	8.11 ± 0.41
Cured	3.47^b ± 0.38	4.74 ± 0.49	4.95 ± 0.47	5.02 ± 0.24	5.81 ± 0.35	6.04 ± 0.43	7.54 ± 0.53	7.82 ± 0.37	8.41 ± 0.43	9.04 ± 0.53
Cured + SA treated	3.47^c ± 0.36	4.65 ± 0.27	4.87 ± 0.41	4.95 ± 0.41	5.55 ±	6.68 ± 0.53	6.91 ± 0.38	7.68 ± 0.35	8.88 ± 0.42	8.96 ± 0.30
Smoked	3.17^c ± 0.51	3.30 ± 0.38	5.14 ± 0.41	5.88 ± 0.49	6.59 ± 0.37	7.00 ± 0.53	7.76 ± 0.28	8.27 ± 0.31	8.89 ± 0.32
Cured + smoked	2.69^c ± 0.37	3.17 ± 0.42	3.91 ± 0.29	5.00 ± 0.38	5.13 ± 0.39	5.69 ± 0.29	6.67 ± 0.32	7.88 ± 0.38	7.90 ± 0.53	8.23 ± 0.44	8.54 ± 0.35	8.93 ± 0.34
Cured + SA treated + smoked	2.69^c ± 0.59	3.17 ± 0.46	3.46 ± 0.34	3.63 ± 0.33	3.78 ± 0.48	3.89 ± 0.41	3.94 ± 0.28	3.99 ± 0.39	4.11 ± 0.42	5.61 ± 0.27	6.30 ± 0.43	7.68 ± 0.33	7.89 ± 0.56	8.23 ± 0.47

*Values are the means ± SD of nine observations.

LDPE—Low density polyethylene, SA—sodium ascorbate, TPC—total plate count.

Mean values with different superscript differ significantly (p < 0.05).

Table 3 Effect of curing, antioxidant treatment, and smoking on sensory characteristics of buffalo meat packed in bags*

Treatments and storage period (days)
0	5	10	15	20	25	30	35	40	45	50	55	60	65	70
Sensory attributes	Controlled sample
Color	6.9^a	6.7	5.3	4.1	3.5	3.1
Texture	7.2^a	6.8	5.5	4.4	3.2	2.9
Aroma	7.5^a	7.2	6.4	5.2	3.6	3.1
OAA	6.9^a	6.9	5.7	4.6	3.4	3.0
Cured meat
Color	7.5^b	7.1	6.7	6.2	5.8	5.2	4.1	3.8	3.4
Texture	7.9^b	7.7	7.4	7.1	6.8	6.7	6.0	5.6	4.2
Aroma	7.5^a	7.4	7.0	6.7	6.1	5.7	5.2	4.3	4.1
OAA	7.6^b	7.4	7.1	6.7	6.3	5.9	5.1	4.6	3.9
Cured + SA treated meat
Color	7.5^b	7.3	6.8	6.5	5.9	5.6	5.6	5.1	4.6	4.1	3.8
Texture	7.9^b	7.7	7.5	7.2	6.9	6.7	6.1	5.8	5.5	5.0	4.3
Aroma	7.6^a	7.5	7.1	6.8	6.5	6.0	5.5	5.0	4.3	4.0	3.7
OAA	7.7^b	7.5	7.1	6.8	6.4	5.9	5.3	4.8	4.5	4.35	3.9

*Values are the means of nine observations.

LDPE—Low density polyethylene, SA—sodium ascorbate, OAA—over all acceptability.

Mean values with different superscript in each sensory attribute differ significantly (p < 0.05).

Table 4 Effect of curing, antioxidant, and smoking on sensory characteristics of buffalo meat packed LDPE bags*

Treatments and storage period (days)
0	5	10	15	20	25	30	35	40	45	50	55	60	65	70
Sensory attributes	Smoked meat
Color	8.1^c	7.9	7.6	7.0	6.7	6.4	6.0	5.7	5.1
Texture	8.2^c	7.9	7.5	7.1	6.7	6.5	5.3	5.1	4.2
Aroma	7.8^a	7.0	6.5	6.0	5.4	5.0	4.7	4.3	3.4
OAA	8.0^b	7.6	7.2	6.7	6.3	6.0	5.3	5.0	4.6
Cured + smoked
Color	8.7^c	8.2	7.8	7.8	7.3	7.3	7.0	6.8	6.4	6.2	6.0	5.9	5.4
Texture	8.6^c	8.6	8.1	7.9	7.7	7.2	7.0	6.7	6.3	6.0	5.4	5.1	4.8
Aroma	7.8^a	7.8	7.6	7.6	7.4	7.1	6.9	6.5	5.8	5.5	5.1	4.8	4.5
OAA	8.4^b	8.2	7.8	7.8	7.5	7.2	7.0	6.7	6.2	5.9	5.5	5.3	4.9
Cured + SA treated + smoked
Color	8.7^c	8.5	8.3	8.0	7.9	7.9	7.6	7.6	7.3	7.1	6.6	6.3	6.0	5.8	5.5
Texture	8.8^c	8.6	8.3	8.3	8.0	7.8	7.6	7.6	7.4	7.4	7.3	7.0	7.0	6.5	6.4
Aroma	7.9^a	7.9	7.8	7.8	7.8	7.5	7.5	7.1	7.1	6.6	6.2	5.8	5.3	5.0	4.6
OAA	8.4^b	8.3	8.1	8.0	7.9	7.7	7.6	7.4	7.3	7.0	6.7	6.4	6.1	5.8	5.5

*Values are the means of nine observations.

LDPE—Low density polyethylene, SA—sodium ascorbate, OAA—over all acceptability.

Mean values of each sensory score with different superscript, differ significantly (p < 0.05).

During refrigerated storage (0°C), pH for the control, cured and, cured + SA treated samples started increasing while there was no such increment in pH for smoked, cured + smoked, and cured + SA + smoked samples. The increase in pH of control, cured, and cured + SA samples was observed for 5 days. This increase in pH was caused by the action of proteolytic enzymes on meat. In the absence of microbial spoilage, the holding of raw, unprocessed meat above the freezing point is known as conditioning or ageing or ripening. Holding has long been associated with an increase in tenderness and flavor due to the action of proteolytic enzyme.[14] The hydrolysis of meat protein is known as ripening. Ripening is responsible for the rise in pH and development of tenderness in meat. In smoked samples, no such rise in pH was observed as smoking is a process that takes time and meat samples are subjected to high temperature (about 50°C). Ripening time is a function of temperature. The lower the temperature, the longer it will take to complete ripening and vice versa. The rate of post mortem glycolysis and ageing increase with increase in the external temperature.[15] Smoking time was 8–9 h, and this much time was sufficient to complete/pass on the ripening phase. The pH of meat samples was found to decrease during the storage period onward to the ripening stage for the first three samples. However, there was a fall in pH of all three smoked samples consistently during refrigerated storage. The study was conducted until the meat samples spoiled. The spoilage conditions were detected by total plate count and sensory characteristics of meat. The minimum shelf life was found to be 20 days for the control meat sample.

Effect on Total Plate Count

Total plate count (TPC) of meat samples has been represented in log TPC/g. The effects of single as well as combined treatments significantly (p < 0.05) reduced the bacterial population as compared to control sample (Table 2). The treatments of either curing + smoking or curing + antioxidant + smoking were found to be significantly (p < 0.05) different from other treatments such as curing or curing + SA or smoking (The difference of log TPC/g values between two treatments was found to be greater than the least square difference of log TPC/g, which was 0.6). Hardwood smoke contains large numbers of phenolic compounds (guaiacol, 4-methyl guaiacol, phenol, 4-ethyl guaiacol, α-cresol, m-cresol, p-cresol etc.), alcohols, organic acid, carbonyls, hydrocarbon, and gases.[16] Phenols have a threefold effect in the smoked meat: (1) act as antioxidants, (2) contribute to color and flavor, and (3) contribute to preservation. Moreover, bactericidal action is pronounced due to the combined effects of heating, drying, and chemical compounds (acetic acid, formaldehyde, and cresols) in the smoke. A total plate count study was continued till the samples were found to be in a spoiled conditions (Table 2). A microbial population of 107/g or above was indicative of spoilage.[17] The shelf life attribute was derived from the microbial population. Similar results were also obtained by Hytiainen et al.[18] They reported that incipiency of spoilage of the meat occurred when the aerobic mesophile count of meat samples reached log 7.0 per gram. Meat is rich in nutrition, and, therefore, it is a center of attraction for microorganism, especially for bacteria due to their desirable pH for growth. Bacteria even at 0°C survive, though the rate of growth is slow. During refrigerated storage, the microbial population increased consistently and finally reached a value beyond 10⁷ per gram. The meat samples were found to be in almost a spoiled condition at this stage.[17] The higher organic compounds, which are valuable in providing nutrition, degraded to simpler compound like fatty acids, amines, carbondioxide, ammonia, and sulphurdioxide. Therefore, meat developed a bad flavor after complete spoilage.

Effects on Sensory Characteristics

Sensory attributes, viz. color, texture, aroma, and overall acceptability, were evaluated by 15 panelists from the Department of Post Harvest Engineering and Technology. The results showed that fresh buffalo meat was light red in color and had an acceptable texture and aroma (Table 3). Curing significantly (p < 0.05) improved the color of meat sample to a bright red. The following reactions are the main causes of color development: (1) sodium nitrate added to meat changes to nitrite by bacterial action; (2) nitrite reacts with H⁺ to form nitrous acid (HNO₂); (3) the nitrous acid that is formed is changed to nitric oxide by compounds present in meat; and (4) nitric acid combines with myoglobin to form nitric oxide-myoglobin, which is bright red in color.[19] Combined treatments of curing and smoking with and without antioxidants was also found to develop significantly (p < 0.05) meat color. The color of cured sample was further enhanced after smoking (Tables 3 and 4). It was pointed out by Watts[20] that the heating effect produced during smoking caused the development of a cherry red color due to the formation of nitric oxide hemochromogen. The mechanism of reaction follows:

Fresh buffalo meat was acceptable in texture and aroma. The treatment of curing and smoking significantly (p < 0.05) improved the texture of controlled meat (Tables 3 and 4). Treatment of smoking in combination with curing and an antioxidant (sodium ascorbate) was found to be significantly different as compared to single treatment of curing (difference of score values for texture was found to be greater or equal to LSD value). During refrigerated storage (0°C), the texture of meat samples started decreasing consistently. The spoilage conditions of meat samples were ultimately detected from the microbial load, color, texture, and aroma. The shelf life of raw meat was found in the present study to be 20 days. The shelf life of treated meat was significantly (p < 0.05) greater than controlled (raw) meat. The shelf life of raw (controlled) meat was found to be 20 days at 0°C, while the shelf life of treated meat samples (cured, cured + SA treated, smoked, cured + smoked, cured + smoked + SA treated) was found to be 30, 35, 25, 30, and 50 days, respectively (Table 2). All the samples were found to be in spoiled conditions after the next five days when microbial load was estimated and sensory characteristics were reported by expert panelists.

Aroma of the meat samples was not found to differ significantly (p < 0.05) in to single and combined treatments. The curing treatment had significant improvement in color while sodium ascorbate and vitamin C showed inhibition of lipid oxidation in beef steak stored in cold room at 4°C for 13 days.[21] Vitamin C treatment showed high lipid stabilities in good beef recording TBA value of 1.5 as compared to control sample (4.0) illuminated display at 4°C for 7 days.[22] Ground buffalo meat treated with 500 ppm sodium ascorbate has significantly higher color score and lower TBARS number as compared to the control and other level of sodium ascorbate. TBARS number was inversely correlated with odor score.

Conclusion

Smoking and curing treatments were found to be antimicrobial while sodium ascorbate was found to be antioxidant (prevent fat oxidation). The combined treatment of all three was not only effective in improving color, aroma, and texture, but also significantly decreased the bacterial population and increased shelf life 30 days at refrigerate storage (0°C). Smoking led to development of organic compounds in the treated sample, formed by thermal decomposition of hard wood. These compounds include phenols polyphenols, carbonyl compounds, and organic acids. Among these compounds some are antimicrobial, some are anti-oxidant, while others are effective in color and aroma development. The condensation of phenols and aldehydes during smoking helped in the formation of resins, which added the glossy-finished surface to the raw and cured meat.

Acknowledgments

The authors gratefully acknowledge the Indian Council of Agricultural Research for providing the funds in Adhoc Research Project that enabled this work to be conducted.