بررسی میزان کربوهیدرات سیب زمینی در زمان برداشت

Introduction
Potato with scientific name Solanum tuberosum. L is a plant that is cultivated as an important
crop in all countries and is known as a source of carbohydrates, proteins, and vitamins in the
human diet. This is a native product of South America and its origin is from Peru. After
wheat, rice and corn, potato is the fourth product in people's food basket, which in Iran
sometimes takes the place of rice and takes second place, which shows its importance in
meeting people's food needs. According to the reports of the Food and Agriculture
Organization of the United Nations, the area under potato cultivation in Iran in 2019 was
more than 164 thousand hectares and the harvested product from this area was about 32.5
million tons. In the food industry, this product is transformed into various products such as
baked potatoes, fried potatoes, potato chips, potato starch, dry fried potatoes, etc.
Agria, Sante, Arinda, Marfona, Jelli, Born, Satina, Milva, Banba, Fontane, Ramos and Esprit
varieties are among the most common potato varieties in Iran.
Due to the increasing expectations for food products with high quality and safety standards, it
is necessary to accurately, quickly and purposefully determine the characteristics of food
مطالعات علوم محیط زیست، دوره xx، شماره xx، فصلx سال xxxx، صفحه xxx-xxx) -10bold-BMitra(
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products. In the apple-potato product, quality assessment after the harvest stage is necessary
to provide a reliable and uniform product to the market, because potatoes, like many other
products, have uneven quality and handling during the harvest stage. - Be At the same time,
the safety and desirability of food play an important role in the food industry and are directly
related to people's health. In addition, a huge part of the potatoes used in the processing
industry is stored, so considering the importance of this food item and the demand of the
people throughout the year, it is possible to meet the needs of the applicants only through
long-term storage with optimal conditions was responsible. Potatoes for the processing
industry must have some requirements such as low sugar content, high dry matter and
specific weight, high antioxidants, light skin color and no sprouting. Storage conditions after
harvesting can cause changes in the chemical composition and quality of the product.
The nutritional and chemical composition of potatoes differs from each other depending on
the variety, storage period, growing season, soil type and pre-harvest nutrition. In general,
potatoes contain 70-80% water and 16-24% starch and contain small amounts (less than 4%)
of protein, fat, anthocyanins, minerals, etc.
Storage conditions after harvesting can cause many changes in the chemical composition of
potato tubers and as a result, change the quality characteristics of the final product. Sugar and
starch are the main components that are affected by metabolism after harvesting in the potato
tuber and may ultimately affect their texture, sensory and cooking properties.
The quality of potatoes and, consequently, the quality of processed products, significantly
depends on the variety and environmental conditions, both during the growing season and
during the storage period.
Although the quality of raw potatoes is determined primarily by the size, shape, color and
attractiveness of the tuber, its quality is mainly determined by examining the quality of the
final product. The quality of processed potato products is evaluated in terms of color, flavor
and texture, and most of their quality depends on the quality of raw potatoes.
By analyzing the relationship between the color of chips, dry solids, sucrose, reducing sugar,
ascorbic acid, protein and storage temperature data, Meza showed that dry solids, reducing
sugar and sucrose in determining the color of fresh potato chips and reducing sugar, tuber
temperature and sucrose content are very important in determining the color of stored tuber
chips, and the relative importance of each of these parameters changes with the variety and
age of potato tubers.
Methodology
5 different varieties of potato were prepared from Arallo Agricultural Research Center
(Ardebil Province) immediately after harvest. Then, data collection was done from different
samples and cultivars (measurement of carbohydrate content) as explained below.
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The carbohydrate content of the samples was extracted using the equipment available in the
central laboratory of Mohaghegh Ardabili University. This process was carried out by the
Schlegel method, in which carbohydrates were extracted using 95% ethanol based on the
sulfuric acid method in each sample. The amount of light absorption of each sample was
obtained from a nano-spectrophotometer device (Nanodrop) with a volume of 1000
microliters (Figure 1) using a cuvette (made by Termo scientific company from the USA) and
the amount of extracted carbohydrates were obtained based on micrograms per millilitre from
the standard curve.
Glucose was used to prepare the standard curve. Serial dilution of glucose was prepared and
color development at 490 nm was controlled for different concentrations of glucose and one
millilitre of distilled water was used as a blank. This standard curve was used to calculate the
concentration of total carbohydrates in the samples. The standard curve had a coefficient of
determination of 0.9955.
For each sample, data collection was done in three repetitions and the amount of absorption
wavelength and then the amount of carbohydrate was calculated.
Conclusion
In order to obtain the number of carbohydrates, the number of the absorption wavelength was
placed in the relationship obtained from the standard curve, and the number of carbohydrates
was obtained in micrograms per millilitre. The results of the analysis of the variance of the
effect of cultivar on potato carbohydrate content can be seen in Table 1. According to the
analysis of the variance table, the effect of variety on potato carbohydrate content was
significant at the 1% probability level.
As you can see, Sante and Esprit cultivars have more carbohydrates than other cultivars.
Also, the carbohydrate content of the Marfona variety was the lowest.
According to the data and results of the research, it was observed that the amount of
carbohydrates in different potato cultivars is different, and Sante and Esprit cultivars had
more carbohydrates at the time of harvest. Also, according to the resulting graphs, it was
observed that the amount of carbohydrates of the Marfona cultivar is lower than other
cultivars. It is recommended to choose a more suitable variety according to the type of
consumption and the importance of quality characteristics for consumption and processing,
according to the storage conditions and time.