A Glance at Food Nutrition Components Analysis

Taizhu Li

Beijing Royal School, Beijing, China

Keywords: Food Nutrients, Protein, Fat, Sugar.

Abstract: With the development of economic, food safety gradually becomes an obvious part drawing our attention in

life. As we all know, the food nutrients show closely connection to our human health. Sugar and fat are key

players in diabetes, cardiovascular and cancer diseases and millions of people are suffering these diseases.

Protein plays a vital role in our body as well, especially for the infants for whom the milk is their main source

of energy supply so the quality of these food should be paid tightly attention to. In food industry, the food

analysis methods should be diverse, and many well-established approaches already worked well for a long-

time history, while during this time new and fantastic techniques always emerging and become a strong

competes to the conventional ways. In this article, we will attempt to gather the existing analysis approaches

for the main food components and show their advantages and disadvantages.

1 INTRODUCTION

The nutritional contents of food are closely related to

human health. Food contains a variety of nutrients

needed by the human body, including sugar, fat,

protein and so on. In terms of their functions in the

body, these nutrients are divided into three parts:

constituent substances, energy substances and

regulating substances. In the nutritional composition

of various foods, only certain components are the

same, and the content of these components in various

foods is also very different. Therefore, a variety of

foods can be combined from these food ingredients,

which is the composability of food ingredients. It is

precisely because of the combinability that the

inherent differences of various foods are created.

With the development of economic, humans

gradually noticed that nutrients in food are needed to

pay more attention since we all know that all the

nutrients are closely to human health. According to

this, the industry adopts many hash policy to control

the quality of the food to ensure the food safety. From

this view, it is important to develop many useful and

efficient technique to detect and quantify all the

components in food. Due to the differences and

complexity of the food matrix, the methods used to

detect food ingredients are also diverse, such as

chromatography, colorimetry, refraction, and so on.

But these methods have their own advantages and

disadvantages. With the rapid development of science

and technology, the research of food nutrients is

gradually deepening, and food testing technology and

testing instruments are constantly updated and

developed. This enables modern food testing to cope

with various complex situations. This article includes

the current detection methods of common nutrients in

food and their advantages and disadvantages.

2 PROTEIN DETECTION

Typically, the Western Blot (WB) has been used as a

traditional way to detect protein(Taylor and Posch

2014). The principle of WB is based on the antibody

recognition, and specific band will be got for each

specific protein in which quantification is an essential

to verify the expression level of each protein (Figure

1 and 2). However, the time costs of this approach are

usually 1-2 days which is a disadvantage when

compared to others. Even though the approach was

improved recently to shorten the time to several

hours(Lin-Moshier and Marchant 2013), the way that

WB is able to detect several proteins not the total

protein contents still make WB not as a popular one

used in food protein contents detection.

So for a long time, total nitrogen content was used

to the determine the protein content of foods in which

Kjeldahl invented a method that has been used

broadly to determine the total nitrogen content. But

the method still costs a relative long time, researchers

356

Li, T.

A Glance at Food Nutrition Components Analysis.

DOI: 10.5220/0011370100003438

In Proceedings of the 1st International Conference on Health Big Data and Intelligent Healthcare (ICHIH 2022), pages 356-361

ISBN: 978-989-758-596-8

mainly focused on the time costa to improve the

process to make it more efficiently. Recently, a

developed method based on an automated

instrumental technique was applied in food protein

contents detection since it is capable of measuring the

food protein concentration in a shorter time than

Kjeladahl methods(Stitcher, Jolliff et al. 1969, Wiles,

Gray et al. 1998). Even though the technique was

developed recently, the technique is based on

Dumas’s method which was created over a century

ago. It is already on its way to compete with the

Kjeldahl method since it costs a shorter time without

the loss of accuracy.

Figure.1: Typical western blot image for probing three different proteins1.

Figure.2: Typical western blot workflow(graph from Creative Biolabs).

A Glance at Food Nutrition Components Analysis

357

3 NUCLEOTIDE DETECTION

Nucleotide is one of the most important biological

molecular in nature, although it is not a nutrient in

food, it is vital to identify some nucleotides which can

be used as markers to some specific species, since

bacterial infection can be very harmful to human

health. In order to control the contaminations of

bacteria, some nucleotide as markers should be

detected in food industry.

Polymerase chain reaction (PCR) is a

conventional technique to amplify the small segments

of DNA, allowing us to have a large amount of DNA

to detect(White, Arnheim et al. 1989).the specificity

of PCR relies on oligonucleotide primers which are

complementary to both ends of the target sequence.

PCR typically involves two sequential amplification

reactions, in which each uses a different pair of

primers. The product of the first amplification

reaction is used as a template for the second PCR,

which is initiated by the oligonucleotides placed

inside the first pair of primers. Applying two pairs of

oligonucleotides makes more cycles to be performed,

thereby improving the sensitivity of PCR. (Rychlik

1993)

After the PCR is done, the product is separated in

a gel and confirm the size of the product so that we

can verify that the contents of nucleotide from

bacteria or some specific species. However, the whole

process usually takes several hours, and the gel

separation must be used to confirm the size and the

amount of the nucleotide. In order to simplify the

whole process and get a better way to quantify the

amount of the DNA, real-time PCR (RT-PCR)

(Figure 3 and 4) was developed to be applied in the

quantification of DNA(Kubista, Andrade et al. 2006).

Fluorescent probes are added in the RT-PCR

system when the reaction is done, the amount of DNA

can be calculated at once. So all the whole process is

completed only in one step as a result that the RT-

PCR is applied broadly in DNA quantification.

4 FAT DETECTION

Fat plays a very important role in human health since

excessive fat from food can increase the risks of

obesity and metabolic disorders in our body thus

causing serious health problems. Obesity is a very

common, severe, and costly disease. In United States,

obesity prevalence was 42% in 2017 – 2018 and the

number is 30% in 1999-2000. This disease always

happens with other severe diseases such as heart

disease, stroke, and certain types of cancer, leading to

huge medical costs to people and government. So,

more attention should be paid to the fat contents in

food. The meaning of total fat is total lipids, including

phospholipids(Holm and Wretlind 1976).

The commonly used techniques are Soxhlet

analysis and acid/alkaline hydrolysis(Khoshtinat,

Koohy-Kamaly et al. 2021). This method is based on

an AOAC Official Methods of Analysis (AOAC).

The first step of it is acid hydrolysis and sample

drying, and then sequentially, the extraction itself on

a Soxhlet device in which the whole process costs

about couple of hours.

A new method relied on an innovative

microwave-assisted extraction (MAE) approach

makes the determination of total fat in cheese

samples. MAE method is statistically equivalent to

other methods, showing good performance and

allows the determination of total fat in 12 samples

simultaneously in 100 min, which shows a much

faster and easier handling than Soxhlet(Adeel, Zuber

et al. 2018).

Figure 3: The steps of RT-PCR(graph from MyBioSource).

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358

Figure 4: Typical results of RT-PCR(graph from Wikimedia).

Figure 5: HPLC-ELSD profile of fructose, glucose, and sucrose standard compounds

5 SUGAR DETECTION

Sugars are caloric and sweet tasting which occur

ubiquitously in our life, including vegetables, honey,

and fruits. Human beings are born with the

preference for sweet taste. Lactose, a type of sugar

naturally existing in milk, in breast milk ensures that

this mainly source of nutrition for babies is palatable

and acceptable. While in food most of the sugars are

chemically added which are monosaccharide or

disaccharide carbohydrates imparting sweet taste. Lot

of foods contain some of each.

Sugars are ones of carbohydrate, and like other

carbohydrates they also contain carbon, oxygen, and

hydrogen molecules. Carbohydrates play an

important role in a healthy diet, as do proteins, fats,

and water. In addition to dietary fiber, in the

condition that carbohydrates are consumed, they will

be digested and broken down to glucose, serving as

an energy source for most organs in whole

body. Glucose is a better source of energy for blood

A Glance at Food Nutrition Components Analysis

359

cells, the central nervous system, and the digestion

system.

Fructose, glucose, and galactose are very common

monosaccharides in which common disaccharides

include sucrose, maltose, and lactose. Quantification

of sugars are now determined by couple of methods.

They include enzymatic method which measures

sucrose phosphorylation and hydrolysis of fructose

and glucose(Finney, Danehower et al. 2005) or

measuring absorbance growth based on commercial

standard assay of sugar kit(Hurtta, Pitkanen et al.

2004). In addition to mentioned above, High

Performance Liquid Chromatography (HPLC)

approach coupled with refractive index detector

(RID) or evaporative light scattering detector (ELSD)

are used as well. HPLC-ELSD shows many

advantages especially for its compatibility, stability,

and sensitivity with gradient elution when compared

to HPLC-RID. Recently, developments in gas

chromatography-mass spectrometry (GC-MS)

equipment and techniques have made this technique

becoming helpful in compositional and structural

analysis of oligomers, polymers and

monosaccharides, especially in food industry and life

sciences areas.

6 CONCLUSIONS

Protein, fat and sugar are the main nutrients in food,

which provide the energy supply to human body.

With the development of technique, many detection

approaches were well established for the past couple

of years, all of this ensure the food safety and make

the food components clear to customers which can

help them know clear about the food components and

have the authority to decide to have them or not.

In recent years, food testing and analysis

technology has developed rapidly, but due to the

limitations of sample pre-processing technology or

the defects of the instrument method itself, many

testing technologies are only at the qualitative or

semi-quantitative level, and the accuracy of the

results needs to be further improved. For example,

continuously improve the detection equipment,

increase the sensitivity and accuracy of the detection

equipment, and optimize the pre-processing methods,

so that the detection results reach an accurate level.

At the same time, actively research and discuss

various advanced detection methods and technologies

according to the continuously developing food types

and develop rapid analysis technologies that can

simultaneously achieve high-efficiency sample pre-

processing and sensitive follow-up detection to meet

the urgent needs of today's food analysis.

In addition to the technique this regard, industry

and the authority should also pay more attention to

the laws in this area so that lot of illegal events can be

avoided. Also customers should also learn more in

order to be able to identify the food label in a good

view.

So for a long time, total nitrogen content was used

to the determine the protein content of foods in which

Kjeldahl invented a method that has been used

broadly to determine the total nitrogen content. But

the method still costs a relative long time, researchers

mainly focused on the time costa to improve the

process to make it more efficiently. Recently, a

developed method based on an automated

instrumental technique was applied in food protein

contents detection since it is capable of measuring the

food protein concentration in a shorter time than

Kjeladahl methods(Stitcher, Jolliff et al. 1969, Wiles,

Gray et al. 1998). Even though the technique was

developed recently, the technique is based on

Dumas’s method which was created over a century

ago. It is already on its way to compete with the

Kjeldahl method since it costs a shorter time without

the loss of accuracy.

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