Determination of the Bio-Chemical Parameters and the Amount of Trace and Toxic Metals in Baby Foods, Jams, Jellies and Juices Available in Bangladesh

Abstract

The thesis entitled ‘Determination of the Bio-chemical Parameters and the Amount of Trace and Toxic Metals in Baby Foods, Jams, Jellies and Juices Available in Bangladesh’ deals with the estimation of bio-chemical parameters, trace and toxic metals in baby foods and some fruit products, e.g. jams, jellies and juices in the view of nutrition, dietary supplements, necessity of essential metals and the harmful effect of toxic metals for infants as well as adults. The results obtained during the course of PhD program have been compiled into five chapters as described below. Chapter One presents the importance of bio-chemical parameters, trace and essential metals and their biological activity in human life. Milk proteins represent one of the greatest contributions of milk to human nutrition. Research indicates that children may develop food allergies if solids are introduced too early. Formula and breast milk provide the perfect balance of nutrients that they need. The knowledge of nutrition in different types of fruit products especially jams, jellies and juices are very significant due to their good food values since these are made from fruit, water and sugar. Jams, jellies and juices provide more essential nutrients in significant amounts as well as some minerals. Our study was to find out some important bio-chemical parameters of baby foods, such as percentages of protein, reducing sugar, non-reducing sugar, total sugar, ash and moisture by using different biochemical methods. The amounts of some trace and toxic metals were also determined by using atomic absorption spectrophotometer (AAS). Chapter Two covers the experimental part which includes the listing of chemicals, physicochemical methods for the determination of biochemical parameters, and the estimation of trace and toxic metals by AAS. The preparation of calibration curves for metal estimation is also described in this chapter. Chapter Three describes the estimation of bio-chemical parameters, trace and toxic metals in baby powder milk and baby cereals. Protein, lactose, acidity, trace and toxic metals were measured in baby foods for comparison to the standard values or the values given in the packet/container. Fourteen samples of baby (0−6 months and 6−24 months) powder milk and ten brands of baby (6−24 months) cereal were analyzed and the result have been discussed in this chapter. Protein found in baby (0−6 months) powder milk of seven brands was in the range of 15.54−18.50%. The amount of lactose and acidity was found to be 51.02 to 62.49% and 0.66 to 1.28% respectively. The content of protein in baby (6−24 months) powder milk was observed between 17.27 and 22.98%. The content of lactose and acidity were in the range of 50.87−58.69 and 1.07−1.20% respectively. The trace (Co and Zn) and toxic (Pb, Cd, Cr, As and Ni) metals in baby (0−6 months) powder milk of different brands were estimated and the values were as follows: Co, 0.02 to 0.04 mg/kg; Zn, 16.95 to 52.86 mg/kg; Pb, 0.12 to 0.42 mg/kg; Cd, 0.01 to 0.02 mg/kg; Cr, 0.03 to 0.16 mg/kg and As, 0.26 to 0.61 mg/kg. Ni in baby (0−6 months) powder milk was found below the detectable limit. The trace and toxic metals in the baby (6−24 months) powder milk was found to be in the range of 0.38−0.47 mg/kg, 5.40−42.00 mg/kg, 0.01−0.04 mg/kg, 3.58−4.67 mg/kg, 0.12−0.24 mg/kg and 0.65−9.20 mg/kg for Co, Zn, Cd, Cr, As and Ni respectively. The metal contents in the baby cereals were observed as follows: Co, 1.2−8.2 mg/kg; Zn, 28.2−659.0 mg/kg; Pb, 0.3−20.4 mg/kg; Cd, 0.04−0.59 mg/kg; Cr, 0.15−0.93 mg/kg; As, 0.58−1.68 mg/kg and Ni, 0.2−32.7 mg/ kg. The bio-chemical parameters of baby powder milks were found to be consistent with their expected values. The concentration of trace metals (Co and Zn) and toxic metals (Pb, Cd, Cr, As and Ni) in baby powder milks were either significantly lower than their tolerance limits, or below their detection limits. These milks can, therefore, be considered as fairly safe for infant health. But the higher concentration of toxic metals in some baby cereal shows alarming signal to their consumer and demands proper investigation of baby cereals after the import. However, the present investigation shows that the baby powder milk which are coming to the markets from abroad contain very negligible amount of harmful metals. Chapter Four deals with the estimation of bio-chemical parameters, trace, toxic and essential metals in jams, jellies and juices available in the market of Bangladesh. The contents of protein, moisture, total solid, reducing sugar and ash were measured in jams, jellies and juices for comparison to the standard values or values given in the packet/container. Total twenty seven samples of jams (nine), jellies (eight) and juices (ten) were analyzed and discussed here……