Potential use of Partially Defatted Sesame (Sesamum indicum L.) to Combat Malnutrition

Food processing plays a vital role in enhancing the nutritional value and increasing the shelf life of any food product (De Araújo et al., 2022; García-Oliveira et al., 2022). Sesame seeds are used in different forms including whole seeds, oil, meal cakes and other by-products for various food preparations worldwide and suitable for making healthy diets (Melo et al., 2021; Nagar et al., 2022; Wei et al., 2022; Bansal et al., 2022). It is one of the most common oilseeds grown and used directly along with its by-products at a large scale (Hafez, 2018). It contains significant amounts of macronutrients (protein) and micronutrients like calcium, iron, zinc, magnesium and phosphorus (Anilakumar et al., 2010; Longvah et al., 2017), that are crucial to maintaining our general health. Sesame has several pharmacological and nutraceutical benefits (Prasad et al., 2012; Ha et al., 2017; Pathak et al., 2017; Sharma et al., 2021). Sesame being a rich source of nutrients and, after processing, can be utilized as a functional meal (Zebib et al., 2015; Aglave, 2018). One of the essential by-products of sesame, sesame oil cake, is a good source of protein (Melo et al., 2021; Tzen, 2021). Pulses lack the amino acids viz. methionine, tryptophanandvaline, whereas sesame seeds are rich in these nutrients (Sharma et al., 2021).
       
Sesame seeds contain anti-nutrients like oxalate, phytate (Longvah et al., 2017), tannin (Abou-Gharbia et al., 1997; Embaby et al., 2011; Okudu et al., 2016; Deme et al., 2017; Aglave et al., 2018; Nagar et al., 2022), etc. which hinder the mineral absorption by the body (Thakur and Thakur, 2019). Anti-nutrients can be decreased by processing methods (Thakur and Kumar, 2017; Thakur et al., 2019; Popova and Mihaylova, 2019) like roasting, microwave heating, dehulling, germination, fermentation, etc. (Nagar et al., 2022) Additionally, these techniques can increase nutrient bioavailability, enhance digestibility and lengthen shelf life.
       
Defatted sesame cake powder is used in bakery products (crackers) to enhance its nutritional value (Hafez, 2018; Lawal et al., 2021), thereby improving protein digestibility as well (Akusu et al., 2020). Food fortified with defatted sesame cake improves nutritional characteristics and enhances microbiological quality, thereby increasing the shelf life of the food products (Prakash et al., 2018). Sesame is emerging as a functional food (Punia et al., 2021) and its byproduct defatted sesame seed cake have more functional properties (Gandhi and Srivastava, 2007) than the full-fat sesame seed (Lawal et al., 2021). Defatted sesame flour can be used to prepare foods for infants and children to prevent malnutrition (Ranganayaki et al., 2012; Uzo-Peters et al., 2018). Hence, defatted sesame seed cake can be further roasted to improve its nutritional and health benefits (Lawal et al., 2021; Sodipo et al., 2021; Nagar et al., 2023). Defatted sesame can be a great source of power-pack food rich in protein (Ranganayaki et al., 2012) and micronutrients such as iron, magnesium and zinc (Prakash et al., 2018) which can be used to combat nutritional deficiencies. Therefore, the present study was planned to evaluate the macro, micro and anti-nutrient contents of defatted sesame cake flour.

The research work was carried out at the Design Innovation Centre, Centre for Converging technologies, University of Rajasthan, Jaipur during the year 2022 (August to December) in the following steps.
 
Collection of raw material
 
Samples of white mechanically dehulled sesame seeds of local variety were procured from the oilseed industry in a 5 kg lot in Jaipur city. The seeds were assessed after cleaning the dirt and extraneous matter.
 
Defatting
 
The whole mechanically dehulled sesame seed samples were defatted using an oil press machine at 200°C temperature and were estimated before (control) and after for macro, micro, antinutrients and total phenolic compounds. The oil yield ranged from 48-60 per cent therefore, it is referred to as partial defatting.
   
Sample preparation for biochemical evaluation
 
After processing, the obtained defatted flakes (by-products) were prepared in powder form in a household mixer grinder and packed in air-tight food-grade containers for different biochemical estimations using standard methods. Macronutrients [moisture (oven drying), total ash (dry ashing), crude protein (Kjeldahl nitrogen), fat (Soxhlet  extraction method), crude fiber (acid-alkali treatment), dietary fiber (enzymatic method) and carbohydrate (difference method)] were estimated by the methods given by AOAC (2019). The micronutrients (iron, calcium, magnesium, zinc) were estimated using ICP-MS as per the methods given by AOAC (2019). Bioavailable iron using the method given by Jain and Mogra (2019). Oxalates and phytates were estimated using the methods developed by Day and Under wood (1986) and Hassan (2011), respectively. The antioxidant activity was determined by estimating the total phenolic compounds using methods given in API (2016). These samples (nine samples each of control and partially defatted sesame) of control and partially defatted sesame seed powder were evaluated for nutritional and anti-nutritional quality.
 
Statistical analysis
 
Paired t-test was applied to check the effect of partial defatting of mechanically dehulled sesame seed. Comparative analysis was done based on the obtained p value at 5% and 1% levels of significance.

Mechanically dehulled white variety of sesame oilseeds had 53.53 g of oil, 24.31 g of protein and 8.66 g of dietary fiber. Partial defatting could reduce fat content to 25.45 g while protein, crude fiber and dietary fiber increased to 40.75 g, 8.87 g and 11.90 g respectively (Table 1).
 

       
The levels of all the macronutrients estimated in defatted sesame seed flakes were significantly higher than whole mechanically dehulled sesame seeds. The increased ash content after defatting revealed that defatted sesame seeds were relatively better in terms of essential minerals like magnesium, zinc and iron especially (Table 1 and 2). Similar results were reported by Hassan (2011) and Bukya and Vijayakumar (2013). There was a significant increase in protein content which shows that defatted sesame seeds can be considered a more concentrated source of plant-based protein for developing food products (Melo et al., 2021; Abbas et al., 2022). With their higher protein and lower fat content, the partially defatted seeds might be favored by those aiming to increase protein intake without a significant calorie contribution from fats (Melo et al., 2021).
 

       
Defatted sesame cake flour was found to be better in micronutrients content when compared with full fat mechanically dehulled sesame as also reported earlier (Hassan, 2011; Uzo-Peters and Akinola, 2018). Defatted sesame meal was found to be having significantly higher magnesium and zinc while calcium and iron content were similar as control seed samples (white mechanically dehulled whole sesame) (Table 2). The bioavailable iron in partially defatted sesame seeds was less than the mechanically dehulled sesame (Table 3) which may be due to increase in oxalate and phytate content after defatting (Makinde et al., 2013). The variations in oxalate and phytate concentration across different sesame cultivars have been reported earlier by various authors (Embaby, 2011; Jimoh et al., 2011; Adegunwa et al., 2012; Makinde and Akinoso, 2013; Bukya and Vijayakumar, 2013; Zebib et al., 2015; Okudu et al., 2016; Om et al., 2020; Obeta et al., 2020; Rahimi and Gharachorloo, 2020).
 

       
Defatting sesame flakes can be roasted or fermented before utilization which will further reduce the oxalate and phytate content and increase the bioavailability of iron (Jimoh et al., 2011; Om et al., 2020). They can also be fermented to enhance the nutrient availability (Makinde et al., 2013; Om et al., 2020; Nagar et al., 2023).

Defatted sesame seed flour is an important functional food (due to presence of sesamol, sesamolin, sesaminol, sesamin, alpha tocopherol, omega 3 and 6 fatty acids etc.), sesame seeds are source of macro and micronutrients to cater nutritional needs of every age group. Defatted sesame seed powder does not taste much fibrous in taste and provide nutty flavor of sesame thereby increasing its sensory quality. Sesame seeds are rich in lysine as well as methionine amino acids. Defatted sesame seed cake if supplemented to cereals or pulses will make a complete protein. Being defatted, sesame seed cake is high in energy, protein and mineral content, it is useful for value addition in low quantities for getting its benefits. Being high in energy, protein, iron, zinc and magnesium, it can be used as dietary supplements for children, adolescents, lactating women and other vulnerable sections of society to reduce protein energy malnutrition and anemia.

Director and Coordinator, Design Innovation Centre (DIC-RU), Centre for Converging Technologies, University of Rajasthan, Jaipur is duly acknowledged for providing necessary facilities.

Authors have no conflict of interest regarding this article.