Chemical analysis of the nutritional value presents the foundation of the practice and science of dietetics and nutrition. However, although most people read the labels on products they buy, they know little about the precision and accuracy of the collective macronutrient evaluations. Bias in food analysis occurs when the individuals responsible for evaluating the composition of food substances express favor or inclination towards the content of the food analyzed. The bias is predominantly brought about by the people trying to show their interest in revealing or hiding the true constituent of the product due to commercial or other intentions. Food analysis laboratories play a significant role in the contribution to food bias as some fail to apply the accepted scientific methods of analysis, leading to distorted results concerning the food composition. The paper will expound on the bias related to food analysis in terms of laboratory results discrepancies, food sampling, as well as chemical and enzyme treatments inhomogeneity.
Bias in the Food Analysis Laboratories
Food analysis laboratories have a marked impact on the development of biases and errors in food analysis due to the misuse of the accepted scientific procedures for evaluating the content of various food substances. Various studies have shown that food analysis laboratories do not apply the recognized food analyzing methods causing biased results regarding the food composition (Pomeranz, 2013). In a study done to investigate the presence of bias in food analysis, a sample of homogenized biscuits was sent to various laboratories in the United States and Europe (Pomeranz, 2013). Each lab was expected to perform the analysis of macronutrients present in the food sample using its usual procedures. Most of these laboratories were either governmental or non-governmental and were regarded as significant players in the creation of the national nutritional data banks (Pomeranz, 2013). The findings for the dry substance and the ash were consistent across all the laboratories. There was certain variation in the content of protein from the sample analyzed (Pomeranz, 2013). In other aspects the consistency in different laboratories was poor. The coefficient of variation (CV) for all the fat content was ranging from 5.6% to 56% (Pomeranz, 2013). As for the total carbohydrate quantity, the CV fluctuated from 10% to 28%, while the CV for all the dietary fiber demonstrated a 24% to 86% difference (Pomeranz, 2013). From the results of this research it can be concluded that the top laboratories give widely varied values of the macronutrients present in the regular food products (Pomeranz, 2013). Most of these variations resulted from various knowledge levels of the workers in these laboratories (Pomeranz, 2013). Thus, there is a necessity to standardize the training of employees in the laboratories to ascertain that they have the necessary skills. The reagents and all the technology used in the analysis of food content should also be adapted to a common standard to ensure that the analytical laboratories produce consistent results to avoid bias and errors in the whole process (Lee, 2012). Therefore, the programs of quality control and materials for reference of certified nutritional concentration are required instantly.
Food Sampling as a Source of Bias in Food Analysis
The validity of the inferences made from the food analysis greatly depends on the procedures used in attaining and conserving the sample. The process of sampling and any consequent separations constitute the largest sources of mistakes and biases in the analysis of foods (Pomeranz, 2013). An ideal sample should be identical in all its fundamental characteristics to those of the original materials it was obtained from (Lee, 2012). In the real sense, a sample is considered acceptable if the features to be studied match those of the original material set by the type of the test (Trevizan et al., 2008). The main steps of the correct sampling include the population identification, from which the sample to be included in a study is obtained. The second step involves selecting and receiving the unrefined samples of the population. The third phase encompasses reducing each of the coarse samples to the size necessary for analysis (Lee, 2012). The research shows that analytical uncertainty is always smaller than the sampling uncertainty and a well-selected sample helps to notably reduce bias and inaccuracies in food analysis. (Trevizan et al., 2008).
There are various types of samples. Firstly, there are random samples, with each part of the food substance being given an equal chance to participate in a study (Trevizan et al., 2008). Sampling done at evenly fixed intervals is easier and broadly utilized, but it involves the chances of bias as well. Systematic samples are suitable for testing the changes in the composition with time or special treatment (Trevizan et al., 2008). Representative samples, however, are mainly obtained from an entirely homogenous substance (Trevizan et al., 2008). In a study that was done to detect and quantify the natural toxicants in feeds and foods unique challenges were confronted by the researchers in the sampling process and the preparation of the sample (Lee, 2012). Several factors make it difficult to get a sample that precisely represents the natural toxins concentrations. These factors include the nature, distribution throughout the whole substance, and the physical features of the material to be analyzed. The other factors include the ability of the material to be sampled randomly, the sampling method used, and finally the size of the sample under the investigation (Pomeranz, 2013). The plans of sampling consist of three constituents: sampling proper, the preparation of the acceptable sample and the analysis of it (Lee, 2012). Generally, sampling plays a major role in contributing to the greatest relative mistake and bias while the process of analyzing is the least flawed.
Several scholars have attempted to research the best practices to reduce the bias and mistakes in food analysis. They also recommend that the laboratory technicians should obtain sufficient samples of the substance so that all the expected determinations can be performed efficiently (Nielsen, Petersen, & Dambmann, 2001). In most cases 250g of a homogenous sample is enough for the analysis. They, anyway, recommend that spices samples should not exceed 100g, and those of vegetables and fruits be enlarged to 1000g (Nielsen, Petersen, & Dambmann, 2001). The storage of samples should also be paid relevant attention for no substantial changes to take place from the time of sampling up to the completion of the analysis. Additionally, the storage containers should be located separately from other packed samples to be easily reached when necessary (Aurand, 2013). For security purposes the legal and official samples should be appropriately sealed to guarantee no one can open them without first damaging the seal (Lee, 2012). The process of sampling food substances being crucial is associated with the largest number of bias and flaws in the analysis of food products.
Bias in the Chemical and Enzyme Treatments
Chemical and enzyme treatments of food substances for analysis pose a significant problem in the process of food analysis. These methods are used in the course of disintegration of various food materials for analytical purposes (Lee, 2012). Pure celluloses, for instance, have proved to be significant in the preparation of food substances originating from plants. On the other hand, carbohydrases and proteases are utilized in solubilizing the components of high-molecular-weight (Nielsen, Petersen, & Dambmann, 2001). Reducing agents, synthetic detergents, dimethyl sulfoxide, phenol, pyridine, and urea are also some of the major chemicals used in solubilizing and dispersing food constituents or foods for analysis (Nielsen, Petersen, & Dambmann, 2001). Another study, that was conducted to determine the amount of each macronutrient in bovine liver and chicken eggs using various chemicals and enzymes, identified deviations in food analysis (Trevizan et al., 2008). The leading cause of this bias was the use of chemicals and enzymes of the same type but from different companies. In this study it was discovered that the process of making enzymes and chemicals slightly differs from firm to firm, which leads to varied food analysis results despite the use of the same treatment substances (Trevizan et al., 2008). The investigation findings revealed that manufacturing industries do not have a strict standard way of producing the chemicals and enzymes used in the food analysis (Trevizan et al., 2008). In another test involving ten food-analyzing laboratories, the same chemicals and enzymes from the same company were utilized and the findings of food components were consistent across all of them (Aurand, 2013). This research proved that using chemicals and enzymes from different companies for food analysis provides diverse results on the same food sample (Aurand, 2013). The research also shows that some of the industries manufacturing these chemicals and enzymes do not use the certified raw materials in their production process with the aim of minimizing expenses and maximizing the profit (Aurand, 2013). Therefore, the government should control the methods that are utilized in the manufacture of chemicals and enzymes that are used in the analysis of food substances to reduce the biased outcomes.
Bias in food analysis is a major problem that requires being addressed with all the seriousness it deserves. The consumers have the right to know the correct components of nutritional content in each food sample for health purposes. Unfortunately, even being regarded as trustworthy information sources, food analyzing laboratories contribute a lot to the development of bias and errors in the analysis of food constituents. They lack sufficient experience, fail to use the accepted or certified methods of food analysis, which lead to bias in the whole process. One more main contributor to food analysis bias is the determination of the correct food sample to be included in the investigation of food components. The research illustrates that obtaining the wrong sample for food analysis also provokes inaccuracies in the results. Therefore, anyone involved in the process of food analysis should have the necessary sampling knowledge for obtaining the right food sample for a study. The last influential factor promoting the bias in food analysis is the chemicals and enzymes used in the process. The studies have shown that these chemicals and enzymes are not manufactured according to standards, adding to the existing bias. Therefore, the government has to play a major role in controlling and regulating this procedure to reduce the misconceptions in food analysis.