Proximate, organoleptic properties and lipid stability of Suya produced from mutton treated with Allium sativum powder

Introduction

Meat, a food rich in protein and other essential food nutrients has the tendency to deteriorate within few hours after slaughtering except it is preserved (Olaoye and Onilude, 2010; Nychas et al., 2008) [1,2] Meat preservation entails several processing procedures. One of the ways of preserving meat is by converting fresh meat to a more shelf -stable product in form of ready to eat delicacy such as suya. In order to produce edible meat products, consumers' interest in relation to their well-being and acceptability should be considered. This can be achieved by the incorporation of safe to eat plant sources such as spice and medicinal herbs into the ingredients. Suya is one of the ready-to-eat meat products of flesh and inerts from all animal species. It is traditional spiced, skewed and roasted boneless meat popular among Hausas in Northern part of Nigeria (Omojola, 2008) [3] . Suya is one of such intermediate moisture meat products that have short shelf life as a result of its handling during and after production (Adesokan et al., 2008) [4] . The usage of synthetic chemicals as preservative in food is no more acceptable to the consumers even though they are effective, their use should be replaced with natural preservatives to reduce the possibility of residual effect on the consumers' physiological well-being (Yang and Ray, 1994) [5] . In order to reduce this menace research should be geared towards the inclusion of natural substances such as spice and herbs into the ingredients used for the meat processing in order to improve quality and safe guide the health of the consumers. Allium sativum (Garlic) is well known as spice and herbal medicine (Javendel et al., 2008) [6] and spices are known to exhibit antioxidant activity due to presence of several phytochemicals (Kochhar, 2008) [7] . The mechanisms of action of spices are on cellular enzymatic pathways (Prasad et al., 2004)) [8] . The aim of this study was to evaluate the impact of Allium sativum powder used as marinade on chemical composition, sensory properties and lipid stability of suya; an intermediate moisture meat derived from West African Dwarf ram.

Materials and Methods

Preparation of suya ingredients

The spices for suya ingredient were procured from a reputable source. Constituents of the ingredient were milled separately and mixed together in an appropriate proportion by the modified method of Omojola (2008) [3] (Table 1).

Preparation of suya

The suya samples were prepared with fresh Biceps femoris muscle (Apata et al., 2013) [9] . 500g each of Biceps femoris muscle of WAD rams were cut into thin slices and threaded unto thin sticks (skewer) of about 13-15 cm long. Fifty (50) skewed suya were made from each treatment group and labeled for easy identification. These were rolled in a bowl containing the mixed ingredients and allowed to coat completely. The coated muscle was marinated for six hours, after which the skewed meat samples were sprinkled with about 5 cm 3 of groundnut oil on each suya sample prior to roasting.

Roasting process of suya: Suya samples were prepared by the procedure of Omojola (2008) [3] . The labeled suya samples were set around a glowing, smokeless fire at 30 cm distance away from the fire point to obtain a desired product. Suya samples were turned at interval of twenty minutes to avoid over cooking with constant sprinkling of groundnut oil on the meat samples until they were cooked to internal temperature of 75 °C.

Determination of chemical composition of suya

Chemical composition of suya sample was determined by the procedures of AOAC (2005) [10] . Crude protein of suya samples was obtained using Kjeldahl method. Ether extract was determined by soxhlet extraction method using petroleum ether. Moisture content was determined by drying 10g of suya sample in an oven at temperature of 105 °C to a constant weight. Ash content of suya was determined by igniting the suya samples in a Muffle furnace at 550-600 °C for 24 hours until ashes were produced.

Determination of lipid oxidation of suya

Lipid oxidative stability of suya samples was assessed by the determination of secondary products of lipid oxidation as 2thiobarbituric acid reactive substances (TBARS) at 7-day, 14day and 21-day post production, using cohesion bioscience assay kit.

Measurement of shear force of suya samples

Suya sample was sheared by the procedures described by Honikel (1998) [11] , at three locations with Warner-Bratzler Vnotch blade shearing instrument.

Sensory evaluation of suya samples

This was conducted according to the method of AMSA (1995) [12] as described by Apata et al. (2013) [9] . A 9-member semitrained taste panel was used to conduct the sensorial properties of the samples. The panelists were provided with unsalted biscuits and water for cleansing of palate in between suya samples. Suya samples were coded and independently evaluated using a 9-point hedonic scale on where 1 = dislike extremely and 9 = like extremely for, aroma, flavour, tenderness, juiciness, texture and overall-acceptability.

Experimental Design and Statistical Analysis

The experimental design of the study was completely randomized design (CRD). Data obtained from this study were analyzed with (SAS, 2002) [13] , while the means were separated using Duncan multiple Range test (Duncan, 1955) [14] .

Results and Discussion

The result of proximate composition shows that the mean crude protein values of suya samples of treatments 1 and 4 were similar. Also, similarity was observed in the crude protein of treatments 2 and 3 while crude protein of treatment 5 was significantly higher (p<0.05) than other treatments. The crude protein values obtained in the study were within the range 32.96 to 33.86% and 28.33 to 35.10% as reported by Oyadeyi et al. (2014) [15] and Ogbonna et al. (2012) [16] respectively. However, pork loin likely contain more protein than mutton (Soniran and Okubanjo, 2002) [17] . The relatively high level of crude protein value obtained in this study may be due to the effect of protein constituents in the ingredients used during processing (Omojola,2008) [3] . The mean ether extract of treatments 3, 4 and 5 were significantly lower (p<0.05) than treatments 1 and 2. The result of ether extract obtained for all samples agreed with previous studies (Ogbonna et al., 2012; Apata et al., 2013; Oyadeyi et al., 2014) [16,9,15] . The result showed that an increase in the level of Allium sativum powder enhanced the reduction of excess fat in suya as a result of sulphur-containing bioactive compounds in Allium sativum (Chowdhury et al., 2002; Niel et al., 1996) [18,19] . The study revealed that there was no significance difference (p<0.05) in ash content among treatment groups. Ash content values of suya samples obtained in the study were closer to the findings of Apata et al. (2013) [9] . Ash content present at an appreciable amount in the suya samples may be due to the contribution of minerals present in Allium sativum powder and other spices used as ingredients. This indicates that suya could serve as a potential source of minerals in human diets. The mean moisture content of suya of treatments 3, 4 and 5 were significantly lower (p<0.05) than treatments 1 and 2. The results obtained for moisture of suya were similar to previous reports (Oyadeyi et al., 2014) [15] however, values were higher than those reported by Ogbonna et al. (2012) [16] . The result also showed that moisture contents of suya were reduced at higher inclusion level of Allium sativum powder this may imply that Allium sativum powder has moisture absorption properties while substantial loss of moisture from the samples during roasting may be due to increase in temperature that enhanced moisture escape from the suya samples thereby, reducing the water activity (a w ) and prevent microbial spoilage in suya to certain extent (Odusole and Adeyanju, 2003; Inyang et al., 2005) [20,21] . However, moisture content of suya, an intermediate moisture meat in this study is still high (Omojola et al., 2004) [22] and it may influence the reduction of its shelf stability where storage facilities are unavailable but on the other hand contributes positively to the sensory attributes such as juiciness, flavour and tenderness (Ogunsola, 2006) [23] . Table 3 shows the results of the sensory evaluation and shear force of suya samples. There was no significant difference (p>0.05) between sensory attributes of suya samples but significantly differs (p<0.05) in overall acceptability as evaluated by panelist using 9-hedonic scale. The study showed that the most accepted sample was obtained from treatment 4 (25% Allium sativum powder). The overall acceptability of suya samples as obtained in the study was not similar with earlier findings (Oyadeyi et al., 2014) [15] . The shear force of suya samples were significantly (p<0.05) influenced by the treatments with the shear force value of suya from treatments 1, 2 and 3 having higher value than 3 kg/cm 2 , an acceptable limit of mutton tenderness, while suya from treatments 4 and 5 were closer to the acceptable limit (Bickerstaffe, 1996; Watanabe et al., 1996) [24,25] . The result of the TBARs of suya treated with Allium sativum powder is shown in Table 4. The results revealed that TBARs values significantly (p<0.05) differs among treatment as storage days advance. It was observed that lipid oxidation increased rapidly in suya samples across treatment groups from 7-day to 21 days. However, the rate of lipid oxidation reduced as the level of Allium sativum in the ingredients increases. Suya sample of treatment 5 (30% Allium sativum powder) had the least TBARS value at 21-day post-production. This implies that high concentration of Allium sativum powder enhanced low rate of lipid oxidation in the muscle, an indication that the powder may be rich in phenolic compounds and flavonoids (Murakami and Ohigashi, 2007; Kochhar, 2008; Eke et al., 2012) [26,7,27] . Lipid oxidation is an important determinant of shelf life of meats and meat products (Morrisey et al., 1994) [28] . TBARS values obtained in treatment 5 at different post-production days (7, 14 and 21 days) of suya samples in this study, were similar to the values of spiced mutton nugget (Mendiratta et al., 2013) [29] . The TBARs values obtained across the treatment groups were below the MDA concentrations range 1.0 to 2.0 mg/kg as threshold values for meat rancidity (Verme and Sahoo, 2000) [30] . The composition of spices used for the control might be responsible for the relatively increase in TBARs values of suya from treatment 1 as the inclusion of Allium sativum powder in other treatments resulted in lower TBARS values than the control samples. This shows that Allium sativum is antioxidative in nature which probably delayed lipid oxidation in the Allium sativum treated suya muscles (Wood et al., 2003) [31] .

Conclusion

The study concluded that the preparation of suya with Allium sativum powder at 30% inclusion into the ingredients had potential to increase the crude protein and ash and reduce the rate of lipid oxidation, while at 25% inclusion, sensorial properties were enhanced.

References

1. Olaoye OA, Onilude AA. Investigation on the potential use of biological agents in the extension of fresh beef in Nigeria. World J. of Microbiol and Biotechnol. 2010;26:1445-1454. DOI:10.1007/s11274-010-0319-5.
2. Nychas GE, Skandamis PN, Tassou CC, Koutsoumanis KP. Meat spoilage during distribution. Meat Sci. 2008;78:7789.
3. Omojola AB. Yield and organoleptic characteristics of Suya (an intermediate moisture meat) prepared from three different muscles of a matured bull. Afr. J. of Biotechnol. 2008;7(13):2254-2257.
4. Adesokan IA, Odetoyinbo BB, Olubamiwa AO. Biopreservative activity of lactic acid bacteria on suya produced from poultry meat. Afri. J. of Biotechnol. 2008;7(20):3799-3803.
5. Yang R, Ray B. Factors influencing production of bacteriocins by lactic acid bacteria. Food Microbiol. 1994;11:281-291.
6. Javendel F, Blaridshad B, Seifarati J, Pourrahimi AH, Baniyaghoub S. The favorite dosage of garlic meal as a feed additive in broiler chickens ration. Pak. J. of Biol. Sci. 2008;11(13):1746-1749.
7. Kochhar KP. Dietary Spices in Health and Diseases (I). Indian J. Physiol. Pharmacol. 2008;52(2):106-122.
8. Prostaglandin Leukot Essent Fatty Acids. 2004;70:521528.
9. Apata ES, Kuku IA, Apata OC, Adeyemi KO. Evaluation of Suya (Tsire) -An Intermediate Moisture Meat Product in Ogun State, Nigeria. J. of Food Res. 2013;2(1):87-93.
10. AOAC. Official Method of Analysis. 14th Ed. Association of Official Analytical Chemist, Washington. DC 2005.
11. Honikel JL. Reference Methods for the assessment of physical characteristics of meat. Meat Sci. 1998;49:447457. http://dx.doi.org/10.1016/S0309-1740(98)00034-5.
12. AMSA. Research Guidelines for Cookery, Sensory evaluation and Instrumental measurement of fresh meat. National Livestock and Meat Board, Chicago, IL, USA 1995. Retrieved from http://www.meat science.org.
13. SAS. Statistical Analysis System. SAS Stat. Version 9 SAS Institute Inc. Garry, NC, USA, 2002.
14. Duncan DB. Multiple Ranges and Multiple F-tests. Biomet. 1955;11:1-42.
15. Oyadeyi OS, Olusola OO, Adebisi TT. Organoleptic And Chemical Evaluations Of Suya (An Intermediate Moisture Meat) Cured With Ocimum Gratissimum Extract. Nova J. of Eng. and Appl. Sci. 2014;3(1):1-6.
16. Ogbonna IO, Danladi MS, Akinmusire O, Odu CE. Microbiological Safety and Proximate Composition of Suya Stored at Ambient Temperature for Six Hours from Maiduguri, Northern Nigeria. Internet J. of Food Saf. 2012;14:11-16.
17. Soniran OG, Okubanjo AO. Physico-chemical and sensory Characteristics of Pork Loin Roasted Cooked at 3 Different Temperatures. Nig Jour. Anim. Prod. 2002;29(1):138-141.
18. Chowdhury SR, Chowdhury SD, Smith TK. Effects of dietary garlic on cholesterol metabolism in laying hens. Poult. Sci. 2002;91:1856-1862.
19. Niel HA, Silagy CA, Lancaster T, Hodgeman J, Vos K, Moore JW, et al. Garlic powder in the treatment of moderate hyperlipidaemia: A controlled trial and metaanalysis. JR Coll. Physicians Lond. 1996;30(4):329-324.
20. Odusole KA, Akinyanju OO. Red suya syndrome -acute intravascular IeAdministration and control. Consumer safety bulletin. 2003;2(2):20-24.
21. Inyang CU, Inyor MA, Uma EN. Bacteriological quality of a smoked meat product (suya). Nig Food J. 2005;23:239242.
22. Omojola AB, Kassim OR, Adewumi MK, Ogunsola OO, Adeyemo GO, Deshiyan AB. Evaluation of the effects of variation in ingredient composition on the eating qualities of suya. Afr J Livestock Ext. 2004;3:28-32.
23. Bickerstaffe R. Proteases and meat quality. Proc N Z Anim Prod. 1996;56:153-156.
24. Watanabe A, Daly CC, Devine CE. The effects of the ultimate pH of meat on tenderness changes during ageing. Meat Sci. 1996;42:67-78.
25. Murakami A, Ohigashi H. Targeting NOX, iNOS and COX-2 in inflammatory cells: Chemoprevention using food phytochemicals. Int Cancer. 2007;121:2357-2363.
26. Eke MO, Arihau CC, Okonkwo TM. Production and Quality Evaluation of Dambu-Nama -A Nigerian Dried Meat Product. Nig Food J. 2012;30(2):66-72.
27. Morrissey PA, Buckley DJ, Sheehy PJA, Monahan FJ. Vitamin E and meat quality. Proc Nutr Soc. 1994;53:289295.
28. Mendiratta SK, Shinde AT, Mane BG. Effect of added vegetable (Carrot, radish and capsicum) as functional ingredients in mutton nuggets. J Meat Sci Technol. 2013;1(2): 71-76.
29. Verme SP, Sahoo J. Improving the quality of ground chevon during refrigerated storage by tocopherol acetate preblending. Meat Sci. 2000;56:403-413.
30. Wood JD, Richardson RI, Nute GR, Fisher AV, Campo MM, Kasapidou E, et al. Effects of fatty acids on meat quality: a review. Meat Sci. 2003;66:21-32.