Lab insight: Vitamin measurement
Important details must also be communicated when food samples are sent to chemical labs for vitamin testing in order to guarantee that the appropriate analytical technique is applied in order to get precise and significant results. This information comprises the types of food being tested (which impacts sample processing), information about the sources of the vitamins (particularly natural and fortifying forms), and information about how the results will be utilised (for product development, quality checks, regulatory and labelling justifications, etc.).
types of vitamins
Vitamins can occur in numerous forms, as Table 1 illustrates, therefore knowing the form(s) of the vitamin in a food is essential to ensuring the proper sample preparation and measurement methodologies are utilised.
The vitamins indicated in Table 1 can be measured in specific targeted forms or as a combination of some or all of the forms using laboratory procedures. In order to incorporate all forms in the reported total amount of that vitamin in the food, it is occasionally necessary to use different analytical procedures. Table describes the most widely used technologies for measuring vitamins in food.Let’s examine vitamin B9 as an illustration of how different vitamin types impact the choice of technique. Vitamin B9, often known as folic acid, comes in two forms: folic acid, which is a synthetic form strengthening, and various naturally occurring forms called folates. The functions of these two types in the human body differ.1. In accordance with the 2020 US regulation1, as well as the current EU regulations2, the disclosed amount of vitamin B9 must be listed in units of Dietary Folate Equivalents (DFE) to account for these various actions. To compute the declared amount in DFE units on nutritional facts panels, the amount of each is required for foods that include significant amounts of both naturally occurring and artificially manufactured forms. The widely used microvitamin technique simply quantifies the total vitamin content, such as folates and
More information about the food’s production process at the production site is needed in order to use the microvitamin approach to determine the vitamin level in DFE units. A more recent and superior alternative is the Final Action method 2011.06, which has been authorised by AOAC International. It uses Liquid Chromatography Mass Spectrometry (LC-MS/MS) to test the amounts of folates and folic acid separately. Since this is the only analytical method that has been validated and directly detects vitamin B9 in the necessary DFE units, CODEX Alimentarius has accepted it as the base method for infant formula.
Vitamin A is another example of how laws affect different forms of the vitamin and led to improvements in laboratory techniques. International Units (IU/serving) were used to express the sum of vitamin A retinol and beta-carotene in the nutritional facts panel of US health care before. Before testing, the lab has to know if one or both of these forms of declarable vitamin A are present in the product since they need to be quantified individually using different analytical techniques (the vitamins have unique chromatographic conditions). The total amount of this vitamin in a food can then be determined using the appropriate approach, or both ways together.
Alpha-carotene and beta-cryptoxanthin were added to the list of four permissible forms of vitamin A starting in 2020 by the FDA Nutritional Facts Panel.. To precisely quantify all four forms and report the total amount of vitamin A, two or even three distinct analytical methods must be used for the analysis. The right procedures can be carried out if one is aware of the various forms, either directly or by looking at the vitamin sources of the item. To get accurate findings, all allowed procedures must be performed if the lab is unsure of the forms of vitamin A.
Measuring vitamin E in food still presents an intriguing analytical problem. Declarable vitamin E in the United States is defined by the FDA as alpha-tocopherol, which comes in two forms: a highly bioactive naturally occurring form and a less bioactive synthetic version.1. Since there isn’t a recognised analytical technique that can distinguish between the two, the FDA mandates that manufacturers create and maintain written records to confirm the quantity of both forms1. To accurately determine the amount listed on a nutritional facts panel, the lab must have access to those records until a technique is created and accepted globally.
You may also like:
Food security in emerging nations: issues and remedies
Are drinks the secret to increasing cannabis use among consumers?
Managing the lack of labour for mushroom picking
sample management
Knowing the different forms of vitamins also enables the laboratory to choose the best sample preparation techniques, ensuring that the vitamins are completely extracted without compromising their integrity. Figure shows the basic plan for sample preparation.
Analytical techniques quantify one, many, or all forms of a vitamin as previously said. As seen in Figure 1, in order to isolate these form(s), the targeted forms must be extracted into a solvent that is compatible with the measurement device, preserves the integrity of the vitamin by having the right pH, and limits elements that can cause deterioration, such as oxygen, light, and certain metals.
The laboratory needs to know whether the vitamins are encapsulated in addition to comprehending the vitamin types found in food. By isolating the vitamin from elements that contribute to its degradation during food preparation, this encapsulation helps prevent vitamin deterioration. From a laboratory standpoint, the kind of encapsulation can need changing the sample preparation procedure in the lab.
Samples sent in for analysis need to be handled carefully since certain vitamins might deteriorate in response to changes in pH, temperature, exposure to light and/or oxygen, and other factors that can be difficult to regulate. The types of vitamins contained in the food as well as the food itself—specifically, whether it is liquid, solid, or dried—determine the best handling and storage conditions.
When homogenising the provided sample by grinding or mixing, extra caution must be used because this may introduce heat or oxygen, which could destroy the vitamins. Because the analytical analysis will only employ a sub-sample of the original sample—sometimes as small as 0.5g—this step is even more crucial. It is advised to handle the sample by keeping it frozen or cool.
Use of analytical results
Each country has its own labelling standards that specify which vitamin types are acceptable to list on nutritional labels. The location of the food’s marketing must be taken into consideration when choosing an analytical method if the results of the analytical testing are to be used for labelling. CODEX Alimentarius provides a list of the analytical techniques that it has determined to be the most accurate for assessing vitamins in various food groups for international trade.4 To guarantee that measurements are conducted accurately and convincingly, your business and the hired laboratories must stay abreast of these regulations.
In summary
The right testing procedures must be chosen in collaboration with product creators and assessors in order to quantify vitamin levels in food with accuracy and integrity. This also holds true for possible pollutants and other nutrients.