ABSTRACT
This research reports the concentrations of essential elements in commercial baby foods and reconstituted fruit juices obtained from Kaduna and Abuja, Nigeria.The concentrations of mineral elements except calcium were determined using a direct reading spectrophotometer while calcium concentration was determined using titrimetric analysis. The values for proximate analysis carried out on six (6)selected classes of commercial baby food samples showed that the moisture content ranged from 1.39 to 3.19%; Ash contentranged from1.04% to 3.15%. Crude protein ranged from 5.25% to 8.75% whereas crude fibrevaried from 0.97% to 4.73%. The crude fat/lipid of the samples ranged from 3.40% to 5.90%. Carbohydrate content ranged from 81.51% to 86.65%..The highest mean value for the concentration of fluoride in the reconstituted fruit juices samples was 0.0030mg/Lwhile the lowest fluoride concentration was 0.0003mg/L.Fluoride concentration inthe baby food samples ranged from 0.0004mg/kg to 0.0033m/kg. However,fluoride was not detected in four samples of the reconstituted fruit juice and three baby food samples. The concentration of potassium determined in the fruit juice samples ranged from 10.33mg/L to 450.04mg/L,while potassium inthe baby foods samples ranged from579.25mg/kg to 4250.00mg/kg. The concentration of calcium in the fruit juice samples ranged from 124.42mg/L to 442.50mg/L. The baby foods samples had calcium concentrations in the range of5445.92mg/kg to 5368.85mg/kg. Magnesium concentration in the fruit juice samples ranged from78.70mg/L to 141.56mg/L. However, its concentration in the baby
foodsamples were higher, ranging from566.08mg/kg to 1150.73mg/kg. The concentration of phosphorus in the fruit juice samples ranged from 272.73mg/L to 795.46mg/L. A higher
vii
concentration of phosphorus was present in baby food samples rangingfrom 2301mg/kg to 9943.46mg/kg. The concentration of iron in the baby food and reconstituted fruit juice samples were low compared to the concentrations of other mineral elements.Iron in the fruit juice samples ranged from3.09mg/L to 34.50mg/L and from 31.25mg/kg to 549.11mg/kg in the baby food. The concentration of zinc was also low in baby food samples, ranging from 2.87mg/kg to 171.49 mg/kg. Zinc was not detected in all the fruit juices and baby foods except in one sample of the reconstituted juice.Positive significant correlations were obtained between F- and Zn (0.770**), NO3- and Mg (0.744**); between K and Ca(0.605*), Mg(0.474*), P(0.548*), Fe(0.580*) in the selected reconstituted fruit juice samples. Positive significant correlations were obtained between pH and NO3(0.502*) at (95%) confidence level where as negative correlations were obtained between Cl and P (-0.615*) and between Mg and Fe (-0.675**) respectively in the baby food samples. Theconcentrations of the studied elements were within safe limits recommended by National Institute of Health and the Institute of Medicine, for foods. Therefore, the commercial baby foods produced from mixed cereals have higher concentration of calcium, potassium and iron.
TABLE OF CONTENTS
itle Page i Declaration ii Certification iii Dedication iv Acknowledgement v Abstract vi Table of Contents v List of Tables xvii List of Figures xviii List of Appendices xix Abbreviations and Symbols xx
CHAPTER ONE
1.0 INTRODUCTION 1
1.1 Baby Foods 1 1.1.1 Classification of commercial baby foods. 3 1.1.2 Composition and nutrient value of cereal grains used in manufacturing of Commercial baby foods.4 1.2 Reconstituted Fruit Juices 5 1.3 Mineral Elements 5
1.3.1 Fluoride 5
ix
1.3.2 Calcium 7 1.3.4Potassiumion8 1.3.6 Magnesium 9 1.3.7 Iron 10 1.3.8 Phosphorus 10 1.3.9 Zinc 11 1.4 Proximate Analysis 11 1.5 Justification of Study 11 1.6Aimsand Objectives of Study12 CHAPTER TWO
2.0 LITERATURE REVIEW 13
2.1 Effects of High and Prolong Intake of Fluoride 14 2.1.1 Chlorides and nitrates 16 2.1.2 Concentration ofFluoride in Reconstituted Fruit Juices 17 2.2Mineral Concentration of Reconstituted Fruit Juices 19 2.3The Need for Consumption of Commercial Baby Food/ cereals 20 2.4Recommended Daily Intake of minerals for Babies and Children 22 2.4.1 Fluoride 22 2.4.2 Calcium 23 2.4.3 Potassium 23 2.4.4 Magnesum 23 2.4.5 Iron 23
x
2.4.6 Phophorus 24 2.4.7 Chloridse 24 2.4.8 Zinc 24 2.5 Fluoride Concentration in Commercial Baby Foods 25 2.6Mineral Concentration in Commercial Baby Foods 26 2.7Proximate Composition of Selected Commercial Baby Foods 29 2.7.1 Moisture content 29 2.7.2 Ash content 30 2.7.3 Crude protein content 30 2.7.4 Crude fibrecontent 31 2.7.5 Crude fat/lipid content 31 2.7.6 Total carbohydrates 32 CHAPTER THREE
3.0 MATERIALS AND METHODS 33
3.1 Sampling 33 3.2 Sample Preparation 33 3.3 Reagents and Apparatus 33 3.4 Preparation of Reagent Solution 34 3.4.1 Standard fluoride solution 34 3.4.2 Standard potassium solution 34 3.4.3 Standard calcium solution 35 3.4.4 Standard magnesium solution 36
xi
3.4.5 Standard iron solution 36 3.4.6 Standard phosphorus solution 36 3.4.7 Standard zinc solution 37 3.5Perchloric acid digestion for samples (for mineral determination) 38 3.6Spectrophotometric Determination of Mineral Elements 38 3.6.1 Determination of fluoride concentration by SPADNS method 38 3.6.2 Determination of potassium concentration by turbidimetrictetraphenzlborate Method 39 3.6.3Determination of magnesium 39 3.6.4 Determination of phosphorus40 3.6.5 Determination of iron41 3.6.6 Determination of zinc42 3.6.7 Determination of calcium by titrimetric analysis43 3.6.8 Determination of nitrates 44 3.6.9 Determination of chlorides 45 3.6.10 Determination of pH 45 3.6Proximate Determination(AOAC,1980)45 3.7.1 Determination of moisture content45 3.7.2 Determination of ash content46 3.7.3 Determination of crude protein46 3.7.4 Determination of crude fibre47 3.7.5 Determination of crude fat/lipid48 3.7.6 Determination of carbohydrates (Pearson,1976) 49
xii
CHAPTER FOUR
4.0 RESULTS50
CHAPTER FIVE 5.0 DISCUSSION 75 5.1 Proximate Composition of Commercial Babyfoods75 5.1.1 Moisture content75 5.1.2 Ash content75 5.1.3 Crude protein content76 5.1.4 Crude fibre content 77 5.1.5 Crude fat/lipid content 77 5.1.6 Carbohydrate content78 5.2 Mineral Concentration in Reconstituted Fruit Juices and Commercial Baby Food Samples79 5.2.1 Fluoride concentration in selected reconstituted fruit juices79 5.2.2 Fluoride concentration in selectedcommercial baby foods80 5.2.3Potassium concentration in selected reconstituted fruit juices81 5.2.4 Potassium concentration in selected baby foods81 5.2.5Calcium concentration in selected reconstituted fruit juices83 5.2.6 Calcium concentration in selected baby foods83 5.2.7Magnesium concentration in selected reconstituted fruit juice85 5.2.8 Magnesium concentration in selected baby foods85 5.2.9 Phosphorus concentration in selected reconstituted fruit juice 87 5.2.10 Phosphorus concentration in selected baby foods87
xiii
5.2.11 Iron concentration in selected reconstituted fruit juice 88 5.2.12 Iron concentration in selected baby foods 89 5.2.13 Zincconcentration in selected reconstituted fruit juice 90 5.2.14 Zinc concentration in selected baby foods90 5.3 Physicochemical Parameters in Reconstituted Fruit Juice and Baby Food Samples 92 5.3.1pH in reconstituted fruit juice commercial baby food samples 92 5.3.2 Chlorides in reconstituted fruit juice and commercial baby food samples94 5.3.3 Nitrates in reconstituted fruit juice and commercial baby food samples 94 5.4 Correlation Analysis 95 5.4.1 Correlation matrices of analyte concentrations in selected reconstituted Fruitjuices95 5.4.2 Correlation matrices of analyte concentrations in selected commercial baby foods96 CHAPTER SIX 6.0SUMMARY, CONCLUSION AND RECOMMENDATIONS 6.1.Summary 97 6.2.Conclusion 99 6.3. Recommendations101 REFERENCES102
APPENDICES 113
xiv
CHAPTER ONE
INTRODUCTION 1.1 BabyFoods Scientific study has proven that breast milk is the perfect food for babies during the first six months of life. It is recommended as the sole source of babies nutrition for the first six months of life as it contains all the nutrients and immunological factors that babies require to maintain optimal health and growth. However, less than 35% of the world’s infants are exclusively breast fed for the first six months and it is recommended that breastfeeding should continue along with complementary feeding until two years of age (WHO, 2009). This is not always possible due to the fact that not all mothers are able to produce sufficient amounts of milk for their babies (Angel et al., 2014). It has been observed that as from six to 12 months, older infants can meet their nutrition requirements with a combination of breastmilk and complementary foods (Butte et al., 2004). Complimentary feeding becomes necessary in order to meet the nutritional needs of the child (Monte and Glugilani, 2004). An estimated one third of a young child’s energy can come from breastfeeding and the remaining two thirds from complementary foods (WHO, 2009; PAHO, 2003).Nutritious complementary foods, also known as baby foods are therefore introduced. Poor nutrition during this critical period of life may increase the risk of growth faltering and micronutrient deficiencies, and may have adverse effects on health and mental development. Hence, improved complementary foods are essential for the child’s normal growth and cognitive development.
2
In recent years, the increase in commercial availability of several types of reconstituted fruit juices and baby foods has resulted in a moderate price reduction of these products thereby leading to an increase in consumption of various baby foods by infants and fruit juices by children. The composition of commercial baby foods and reconstituted fruit juices can be very different from the foods that make up the diet of the general population and therefore information is needed on the nutritional adequacy in terms of the levels of many mineral and elements in these foods. These mineral ions and or trace elements can be divided from a dietary point of view into three groups; the essential trace elements (micronutrients) which are constituents of hormones, vitamins and catalysts required by enzyme for metabolic processes in the cells; the possibly essential trace elements and the non-essential trace elements, made up of the toxic and the non-toxic elements which have no metabolic functions in the living organism (Schrauzer, 1994).
Commercial baby foods can be described as any soft, easily chewed and digested food prepared from a powder formula( processed grains, modified starch, fruits and vegetables) into a liquid paste made specifically for babies/children between the ages of four to six months and two to three years or above of age (WHO, 2009) . These foods are usually made mainly from processed grains; usually milk or any form of protein such as soybeans powder is added during preparation before consumption in order to provide a complete protein meal needed by children. These baby foods comes in multiple varieties, textures and tastes; it may be home made, or it can be purchased from markets or retail outlets.Commercial baby foods can be classified according to the type of grains used for its formulation, such as wheat based, rice, corn or maize, guinea corn, millets, barley, a combination of two or three of types of grains, a combination of grains and fruits(banana,
3
apples etc), modified starch, a combination of any grain with protein powder (soy beans, groundnuts). All commercially available baby foods are to provide the required nutrients as recommended dietary intake (RDI) of minerals for babies and young children (Bermejo et al., 2000). 1.1.1 Classification of commercial baby foods Commercial baby foods are usually prepared mainly from a variety of starchy grains (cereals) as the base ingredient. Classification is therefore based on the type of cereal (milled grain or combination of grains) used. This should constitute at least 50% of the final mixture on a dry weight basis. The foods are fortified with sufficient amount of nutrient supplements or other adjuvants that make them suitable to be consumed by infants and young children who are over 6 months old.These cereal-based commercial baby foods meant for infants and young children have to be prepared for consumption with milk or other appropriate nutritious liquids. The most familiar grains used for making a category of baby food cereals include maize or corn, rice, wheat, millet, oats and barley.
Wheat based baby food is a type of baby food made primarily from wheat grains( whole or processed). Wheat cereal typically contains more fiber than most other types of cereal. This key nutritional ingredient can help children feel full between meals on a lower amount of calories(Baubliset al., 2000).Rice based baby foodare primarily made from rice grain which are either whole or processed. A rice based baby food is usually easy to digest, gluten free and are therefore the least likely to cause allergies in children. They also serve as a good option for kids with sensitive digestive system. Maize or corn based baby foods are also manufactured from maize (whole or processed). Mixed cereal based baby foods are usually a combination of two or more varieties of grains to produce a unique flavor, texture and nutritional
4
quality for the kids.High protein cereal-based baby foods are a combination of any grain (maize, wheat, rice) with a high amount of protein such as soybeans, milk, peanuts that form the bases for this type of foods which are or have to be prepared with water or other appropriate protein -free liquid to be consumed by babies and young children.Modified starch based baby food are most often referred to as corn starch that has been chemically treated or altered to produce a thick smooth paste when prepared for consumption. Most of these baby food products prepared from modified starch are gluten free. Fruit based baby foods are a blend of dried, preserved fruits processed into powder form added to any cereal of choice(maize, wheat or rice) by the manufacturer to produce a blended meal for babies and young children( Siegaet al., 2010). 1.1.2 Composition and nutrient value of cereal grains used in the manufacture of commercial baby foods
Cereals belonging to the complex carbohydrates food group are rich sources of minerals, vitamins, carbohydrates, oils, proteins and fats. Whole cereal grains have an outer bran coat, a starchy endosperm, and a germ. Cereals are enriched with niacin, iron, riboflavin and thiamine, and most cereals have abundant fiber contents, especially barley, oat, and wheat. Cereal consumption also means an intake of high amounts of protein, for infants and children, baby food cereals that are iron fortified are often eaten with milk that makes for a protein-rich meal and also said to be the premium solid foods for infants (Rampersaud et al., 2005).
5
1.2. Reconstituted Fruit Juicesand Drinks These are nutritious foods which offer great taste and are of health benefits because they are important source of mineral elements (Gililandset al., 2003). Baby foods and reconstituted fruit juices that are beneficial to both babies and young children’s diet should contain significant amounts of vitamins A, B, C, and D, and mineral elements such as Fe, Ca, Mg, K, and accepted recommended doses of Na, F-, Mn, Zn, P and Cu (Marzec and Zareba, 2005). However, these products contain varying amount of these minerals and hence are of varying qualities. The content of these mineral elements has become an issue of growing concern (Njenga and Kariuki, 2004).Diet is the main source of trace element (Dim et al., 2004). Many elements are present in foods naturally, or through human activities, such as processing, storage, farming activities and industrial emission (Fein and Falci, 1999). To maintain the physiological and metabolic processes of the body, it is recommended to take appropriate amounts of these mineral elements, since deprivation can lead to diseases; whereas excessive intakes may adversely affect the human metabolic function (Orkason and Sandstoerm, 1995). At high concentrations, these essential elements can lead to poisoning of human body (USEPA, 2004). 1.3. Mineral Elements 1.3.1. Fluorine
Thisis naturally found in water as fluoride in varying amounts, depending on the geological, chemical, and physical characteristics of the aquifer. It is also present in various environmental and food samples. Small amounts of fluoride are vital for the human body and beneficial in the prevention of dental caries but it is toxic in larger amounts.
6
According to guidelines published by the World Health Organization (WHO, 1984), fluoride is an effective agent for preventing dental caries if taken in optimal amounts. However a single optimal level for daily intake cannot be agreed because of the nutritional status of individuals which varies greatly and influences the rate at which fluoride is absorbed by the body. A diet poor in calcium, for example, increases the body’s retention of fluoride.The lethal dose for adults is 0.20-0.35g per kg body weight, (Tokaliogluet al., 2004). Excessive amounts of fluoride can enter the human body by means of polluted air, water and through the food chain, (Tokaliogluet al., 2004). An additional source of fluoride for human is toothpaste containing 0.1% fluoride and water fluoridation (addition of fluoride in the form of NaF to drinking water).
Water is a major source of fluoride intake. The WHO (1984) guidelines suggested that in areas with a warm climate, the optimal fluoride concentration in drinking water should remain below 1 mg/litre (1ppm), while in cooler climates it could go up to 1.2 mg/L. The differentiation is derived from the fact that perspiration is more in hot weather and consequently more water is consumed. The WHO guideline value for fluoride in water is not universal, for example, India lowered its permissible upper limit from 1.5 mg/L to 1.0 mg/L in 1998. In many countries, fluoride is purposely added to the water supply, toothpaste and sometimes other products to promote dental health. It should be noted that fluoride is also found in some foodstuffs and in the air (mostly from production of phosphate fertilizers or burning of fluoride-containing fuels) so the amount of fluoride people actually ingest may be higher than assumed. It has long been known that excessive fluoride intake carries serious toxic effects. Scientists are now debating whether fluoride confers any benefit to humans at all (Poureslamiet al., 2008).
7
1.3.2. Calcium Calcium is the most abundant mineral in the human body. The body stores about 99% of its calcium in the skeleton (bones and teeth), where it serves both structural and physiological roles. It is very important in human metabolism, making up about 1-2% of an adult human’s body weight. In addition to its widely known role in bone structure, calcium is used to help control muscle and nerve function, as well as to manage acid/base balance in our blood stream. Calcium-rich foods therefore play important roles in many aspects of our health that extend far beyond the specific area of bone health (Barba and Russo, 2006).
The most obvious need for calcium is to help build and maintain strong bones. However, calcium is also important for blood clotting, muscle contraction, nerve transmission, and maintenance of normal blood pressure. This explains the importance of calcium intake to human life. Calcium requirements are affected substantially by genetic and other dietary constituents. The interactions of these factors make identification of a single unique number for calcium requirement for all children impossible (NIHCC, 1994; IMFNB, 1997). Calcium is an absolutely critical nutrient in regulating acid/alkaline balance in the blood. When blood pH starts getting low (down to 7.35 from a baseline of 7.4), calcium is released from the bones to regulate the acid / base balance. A complex set of hormonal interactions manages this process, and it is tightly regulated. The pH of blood is of critical importance to sustain life, and controls processes as varied as breathing rate and the ability to transport oxygen in blood cells (Cook and Friday, 2003). It is recognized that a very low calcium intake can contribute to the development of rickets in infants and children,
8
especially those consuming very restrictive diets such as macrobiotic diets (Dagnelieet al., 1990) even though there are no reliable data on the lowest calcium intake needed to prevent rickets or on the relationship among ethnicity, Vitamin D status, physical activity, and diet in the causation of rickets in children fed with low-calcium diet (Legiuset al., 1989). There is also some evidence that calcium supplements may be helpful in reducing the risk of colon cancer, regulating heart rhythms and treating premenstrual syndrome. The daily intake for calcium is between 200mg/day to1300mg for babies of months through to children of 16years of age (IOM, 2004/2007). Calcium is usually well tolerated if the stated doses are not exceeded. 1.3.4 Potassium
Potassium is necessary for the function of all living cell, potassium ion diffusion is a key mechanism in nerve transmission and potassium ion depletion in human body results in various cardiac dysfunctions (Murray, 2006). Potassium is an essential mineral that works to maintain the body’s water and acid balance. As an important electrolyte, it plays a role in transmitting nerve signals to muscles, muscle contractions, fluid balance, various chemical reactions and in the maintenance of normal blood pressure (Webster et al., 2010). Most of the ingested potassium (80-90%) is excreted in urine, the rest being excreted in faeces and sweat (Holbrook et al., 1984; Pietinen, 1982). Potassium filtered in the glomeruli of the kidney is mostly reabsorbed. The potassium in urine results from secretion into the cortical collecting duct, under control of the hormone, aldosterone. High plasma levels of potassium stimulate release of aldosterone to increase the secretion of potassium.Potassium requirements can be affected by climate and physical activity, the use
9
of diuretics, and the intake of other electrolytes, notably sodium. Potassium blunts the effect of sodium chloride on blood pressure, mitigating salt sensitivity and lowering urinary calcium excretion (Su et al., 2001). Given this interrelatedness, requirement for potassium depends to some extent on dietary sodium. However, the ideal sodium: potassium intake ratio is not sufficiently established to use in setting requirements. Its deficiency is usually rare but since many brands of baby foods and reconstituted fruit juices are now fortified with potassium and calcium to increase their nutritional value, there is concern that high intake of potassium poses a risk factor for chronic diseases (Webster et al.,2010). High potassium intakes can cause gastrointestinal discomfort and stress that may include ulceration and perforation (Lambert and Newman 1980; Pietro and Davidson, 1990). High level of potassium can cause a condition known as hyperkalemia. The concentration of potassium in blood is more than the kidneys can eliminate. Based on research by the Linus Pauling Institute (LPI, 2007) ingestion of more than 18 grams of potassium per day can cause this mineral to accumulate, resulting in kidney failure. People with hyperkalemia may experience tingling of their extremities, weakness or cardiac arrhythmia, or abnormal heart rhythm that can be deadly. Arrhythmia can also arise from the resulting hyperkalaemia, ( Suet al., 2001, Ray et al.,1999). 1.3.6 Magnesium
Magnesium is one of the most abundant minerals in our body, which needs it for over 300 chemical processes. About half of the magnesium in the body is locatedin the bones. For children whose bones are still growing and developing rapidly, it is crucial that their diets
10
provide enough magnesium to help them grow healthy and strong(Rude and Shils,2006).According to the L P I (2007), magnesium is used in a variety of functions, especially in the metabolism of energy from food. This is important for children who are very active and need plenty of energy. Magnesium is also important for DNA synthesis, which enables cells to reproduce, helping children’s growing tissues. Finally, magnesium works with vitamin D and calcium to help build strong bones. Vitamin D helps aid the absorption of magnesium into the blood, which then travels to our bones. 1.3.7 Iron Iron is a nutrient that is essential to babies and young children’s growth and development. Iron helps move oxygen from the lungs to the rest of the body and helps muscles store and use oxygen. Babies are born with iron stored in their bodies, but a steady amount of additional iron is needed to fuel a child’s rapid growth and development (WHO, 1997). 1.3.8 Phosphorus
Phosphorus is a mineral that makes up 1% of a person’s total body weight. It is present in every cell of the body. Most of the phosphorus in the body is found in the bones and teeth.The main function of phosphorus is in the formation of bones and teeth. It plays an important role in how the body uses carbohydrates and fats. It is also needed for the body to makeproteinfor the growth, maintenance, and repair of cells and tissues. Phosphorus also helps the body make ATP; a molecule the body uses to store energy (Mason,2011).Phosphorus works with the B vitamins. It also helps with the following; kidney function, muscle contractions, normal heartbeat.
11
1.3.9 Zinc Zinc is an essential nutrient, important for proper growth and development in children. Zinc is also needed for enzyme and immune function, wound healing and protein synthesis. According to IOM (2001), it is important to consume zinc every day since the body does not efficiently store it. The amount of zinc a child requires is based on his or her age and gender. Zinc deficiency can lead to developmental delays. Zinc is a trace element essential to the health and formation of a child’s brain (AJCN, 2001). The amount of protein in a child’s diet is a contributing factor to the efficiency of zinc absorption as zinc binds to protein.
1.4 Proximate Analysis (Crudenutrientanalysis)
The proximate or Weende analysis of food is a quantitative method to determine different macronutrients in food stuff, however it also gives us an idea of its nutritional value. Basically it is the partition of food compounds into six categories by means of common chemical properties. The categories are moisture (crude water), crude ash (CA), crude protein (CP), ether extracts (Crude fats or lipids; EE), crude fiber (CF) and carbohydrate ( nitrogen free extracts (NFE). 1.5 Justification of Study
Commercial baby formulas/foods, bottled water, and beverages such as reconstituted fruit juices are sometimes low in essential mineral elements quality and also contain higher concentrations of elements/ ions such as fluoride, chloride, and high acidity levels which can be harmful as reported in several literatures (Monte and Glugilani, 2014;Ayivoret al., 2011; Adriana and Dana, 2013) . It is unfortunate that there is no verifiable way to know
12
precisely how much of these are being ingested by babies and children through various commercial baby foods and drinks. Exposure is therefore far more widespread than most people are aware. There is need for awareness in this area in order to ensure that these products do not contain high or low amounts of the essential elements that exceed or fall below the recommended values. It is therefore imperative to continuously monitor their levels in varieties of these products so as to ensure that the concentrations of these elements are within the permissible limit recommended. 1.6 Aim and Objectives of Study The aim of this research work is to carry out proximate analysis and evaluate the mineral contentof selected classes of commercial baby foodsand reconstituted fruit juices. 1.7 Objectives of Study The following are the objectives of this research work
a. To carry out proximate analysis on the major and frequently consumed classes of commercial baby foods.
b. To determine the concentration of the essential mineral elements calcium and potassium, magnesium, iron, phosphorus, zinc, fluoride, chlorides and nitrates in different brands of selected commercial baby foods and reconstituted fruit juices.
13
IF YOU CAN'T FIND YOUR TOPIC, CLICK HERE TO HIRE A WRITER»
