Mineral contents of barley grains and its processed foods (kolo, porridge, bread and injera) consumed in Ethiopia

Abstract

ABSTRACT. Barley (Hordeum vulgare L.) is one of the most widely cultivated stable food crops in the world. Barley grain samples were collected from four selected areas (Bahir Dar, Bure, Finote Selam and Debre Markos) of Ethiopia and four types of processed food (kolo, porridge, bread and injera) were prepared from it. The levels of essential and non-essential metals in barley grains and its processed food were determined by microwave plasma-atomic emission spectrometry after wet digestion with a mixture of HNO3 and HClO4 (5:1, v/v). The concentration (mg/kg dry weight) in the barley grains were in the ranges K (5482-6516), Mg (546-643), Ca (445-684), Mn (7.31-9.80), Fe (127-439), Cu (0.88-1.86), Zn (42.8-56.8), Pb (0.39-2.73), Cd (3.01-4.66). The concentrations of all the metals in the four types of processed barley foods showed variation among each other. The results indicate that Ethiopian barley grains and its processed foods are good source of essential metals.
 
 KEY WORDS: Barley, Hordeum vulgare L., Processed foods, Macro-minerals, Micro-minerals, Toxic metals
 
 Bull. Chem. Soc. Ethiop. 2021, 35(3), 471-484.
 DOI: https://dx.doi.org/10.4314/bcse.v35i3.1

The Ethiopian snack food (‘Kolo’): Existing knowledge and research directions on processing practices, quality and consumption

“…As indicated in Table 1 below, barely consists of both micro and macro nutrients, of which the primary components are carbohydrates, proteins, lipids, and minerals, along with a number of secondary metabolites such as vitamins and phenolic compounds [ 7 , 18 , 19 ]. Barley grain consists of about 65–68% starch, 10–17% protein, 2–3% free lipids, 4–9% β-glucans, and 1.5–2.5% minerals, and total dietary fiber ranges from 11 to 34% containing soluble dietary fiber within 3–20% [ 4 ]. It may be difficult to put the actual composition of barely, the composition may be affected by the types of species, growing area, and fertilizer used [ 20 ].…”

“…Generally, during heat treatment of grains like barley, different reactions could be developed, such as millard and hydroxyl-methyl furfural, which are responsible for the desirable color and flavor change of roasted grains [ 41 ]. On the other hand, during heat treatment, toxic, carcinogenic, and neurogenic compounds like acrylamide are developed due to the pre-cursor of the Millard reaction [ 4 ].…”

“…Similarly, in India, roasted barely and legumes are used as snacks and to prepare other foods [ 1 ]. Different snack foods are prepared and consumed in Ethiopia, such as popcorn [ 2 ], roasted maize [ 3 ], extruded products [ 1 ], and Kolo [ 4 ].…”

“…Since Kolo is prepared from cereals and legumes, its nutritional profile may be high. Few research studies have indicated that Kolo has numerous health benefits, including sources of energy due to the composition of barely and other legumes [ 7 ], decreasing blood cholesterol, controlling the glycemic index, and antioxidant activity due to its high fiber content [ 4 ]. It also has also, iron and zinc (up to 60 ppm) than other major cereals, a higher vitamin A and E content, and approximately 3.3 calories per gram of energy [ 8 ].…”

“…In addition, the consumption of Kolo has been increasing more than ever before. In the past, Kolo was used when there is different events such as marriage, birthdays, and funeral ceremonies were always observed in addition to national and religious holidays [ 11 ], but recently it has been used during many official meetings or while traveling [ 4 ]. University students have used it as a snack food when they are away from their parents.…”