Standardization of cut size and pre-drying time of beef to mainstream pastoral processing in Kenya’s meat industry

Sub-Saharan Africa has an estimated 20 million pastoralists who depend largely on livestock and livestock products for income and food (Wellard-Dyer 2012). In Kenya, there are approximately 4 million pastoralists (Kirkbride and Grahn 2008) with an estimated livestock worth of US$ 800 million per year (Lindqvist and Verba 2009). Population-wise, the Somali, Turkana and Maasai are the main pastoral communities in Kenya (KNBS 2009). The distribution of these communities is shown in Figure 1.

Processing and preservation of meat by pastoralists is done locally in the villages, on demand, mostly by women who rely on rudimentary technologies. The meat does not find its way to the formal market because of the challenges of difficulties in package handling and unstandardized, unoptimized quality in processing and storage. The processing is mainly based on indigenous knowledge and the packaging lacks the finesse and the attractiveness of the modern meat package. The size of the cut varies extensively, between and within communities, even for the same product. The packaging used moreover may expose the products to vagaries of the weather, increasing the susceptibility to autoxidation of the fat that the product is abundantly associated with. The packaging used for these products has been demonstrated in our earlier publication (Gichure et al. 2015). Currently, less than 5% of these products are marketed, mainly in the informal markets within the communities, while the rest is consumed at home. The products are not able to surmount the restrictions of the formal market due to various limitations already described (Gichure et al. 2016). In these communities, women rarely own resources, may have less education and cannot access modern infrastructure. This additionally limits their participation in the formal meat products value chain. Previous research on consumer willingness to pay for pastoral meats indicate that finely chopped meat that is tender is most preferred (Wanyoike et al. 2009).

An earlier study reported that the most popular methods of processing and preservation in the pastoral regions of sub-Saharan Africa are deep-frying and sun-drying (Gichure et al. 2014). These methods are considered part of traditional heritage in provision of high energy and protein diets (Lokuruka 2006). In the past decade, studies have been conducted on optimization of the quality traits of these products, but most of the studies have been limited to sun-dried products. However, as earlier stated, this practice only exists in the rural areas. In sub-Saharan Africa, pastoralists cut lean meat into thin strips, which are exposed to direct sunlight for drying. Depending on the community, the stripes may be marinated, salted or even grilled during the process while drying may take up to five days (Fonkem et al. 2010). In the last two decades, solar driers are increasingly replacing sun-drying as they improve quality and safety of dried products, in addition to significantly reducing the drying time.

Globalization and urbanization have introduced deep-fried poultry and fish products with considerable success in urban centres over the recent decades. This would indicate a possible opportunity for deep-fried beef, goat and camel snacks which are traditionally processed and consumed in the rural areas of the pastoral regions, opening an opportunity for them to be mainstreamed into the commercial meat chains. This would in turn boost income generation by the pastoral communities, especially by the women who are the main processors.

Deep-frying is considered more of a cooking and dehydration process in which the frying media, the oil, attains 160 °C to 180 °C. Deep-frying involves simultaneous heat and mass transfer processes (Sosa-Morales et al. 2006). These processes result in extensive changes in product appearance and physical properties, changes which are dependent on the time-temperature and the size of meat chunks (Sosa-Morales et al. 2006; Ziaiifar et al. 2008). During frying, protein are denatured, water vaporized and a crust formed on the product surface; hence, deep-fried snacks have characteristic flavour, texture, cooking effect and satiety as reported by Colmenero et al. (2003) and Acebron and Dopico (2000). The flavour, colour, texture and appearance of deep-fried meats result mainly from protein-carbohydrate interactive reactions (Dobarganes et al. 2000; Choe and Min 2007). Deep-frying by pastoralists is often preceded by pre-drying in the sun to cut down on the moisture content and therefore reduce the oil damage during frying.

Animal fats have been used as frying medium for a long time by pastoralists; however, concerns by urban consumers about cholesterol levels in food and increasing demand for convenient ‘snack-like’ products have prompted a shift to the use of vegetable oils as frying medium (Gichure et al. 2014). In particular, there is use of saturated vegetable oils which are more thermally stable, have better heat transfer coefficient, are less susceptible to oxidation and are cheaper than unsaturated vegetable oils (Gichure et al. 2015; Ziaiifar et al. 2008). From this review, the study used palm oil as the frying media to capitalize on its high saturated fatty acid content, hence better heat transfer coefficient.

Hydrolysis, oxidation and polymerization may occur during the deep-frying process, and these influence the sensory and chemical qualities of the product (Choe and Min 2007). Hydrolysis and oxidation may cause production of free fatty acids and hydroperoxides which are unstable and may break down further into various compounds which consequently produce off-flavours, leading to a stale, rancid flavour in foods (Angelo 1992). The residual fat in the final products increases susceptibility to oxidative and hydrolytic deterioration during storage.

This study was designed to standardize the size of cut and pre-drying time with a view to developing the most acceptable product quality with regard to physico-chemical characteristics and sensory acceptability. This would enable product mainstreaming into the formal market for greater income generation by pastoral communities from their livestock production.