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DETERMINATION OF OHAUS MOISTURE BALANCES

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MOISTURE BALANCES

Introduction

Water is a means of transport for cellular nutrients and their waste metabolites, facilitates the transport of CO2 and O2 gases, their quantity, molecular form and their location within the food product, are factors that significantly affect their characteristics specific as appearance, texture, color, etc.

Moisture determination

There are many methods for determining the moisture content of food, varying in its complication according to the three types of water and there is often a poor correlation between the results obtained.

However, the generality of the methods gives reproducible results, if the empirical instructions are followed faithfully and can be satisfactory for practical use.

The methods can be classified as by drying, distillation, by chemical and instrumental methods.

Determination of humidity by direct heating

objective

Determine the moisture present in a food sample by a drying process, in this case, direct heating.

Basis

The stove has the ability to raise the t and keep it constant, in order to eliminate the moisture present in food for a long period of time.

Conclusions

We can conclude that the sample to which the moisture determination was performed contains a moisture percentage of 9.0351%, which is why it is within the parameters indicated.

The climatic humidity conditions that can influence this result must be taken into account.

ACCORDING TO THE OFFICIAL MEXICAN STANDARD NOM-147-SSA1-1996, GOODS AND SERVICES. CEREALS AND ITS PRODUCTS. CEREAL FLOORS, SEEDS OR SEMOLINES. FOOD BASED ON CEREALS, EDIBLE SEEDS, FLOURS, SEEDS OR SEMOLINES OR THEIR MIXTURES. BREADING PRODUCTS. SANITARY AND NUTRIMENTAL PROVISIONS AND SPECIFICATIONS.

A minimum weight is determined by dividing the standard deviation of repeatability (Rstd) of the balance by the required accuracy. In some cases, a safety factor is applied (for example, USP uses 2 x Rstd). To weigh a 50 mg sample, it could be assumed that a device with a readability of 0.1 mg is quite sufficient. Is this correct? Let’s look at an example to find out. If the maximum uncertainty tolerance is 0.1%, and the Rstd value of the balance is 0.1 mg, then the minimum weight would be equal to 2 * 0.1 mg / 0.001 or 200 mg. Therefore, a 0.1 mg device would be insufficient to meet the accuracy requirements established for this example, and a device with a readability of 0.01 mg should be used.

In this case, a semi-micro device, such as the Ohaus Moisture Balances, would be needed to ‘accurately’ weigh the 50 mg samples. In fact, the OHAUS Explorer equilibrium guarantees that samples can be weighed up to 20mg (in real cases, up to 10mg after an appropriate rating),

while maintaining compliance with the minimum weight standards USP41. In addition to their excellent weighing performance, OHAUS Explorer’s semi-micro scales contain features that help ensure maximum weighing accuracy, such as antistatic devices. Static accumulation can be a substantial source of error when weighing small samples. The Explorer series also contains several features that make balances easy to use and suitable for use in regulated environments,

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