CC BY
0УДК 579.2 Kukhar E. V., Talgatkyzy N.
Kukhar E.V.
doctor of Biological Sciences, Acting Professor, Headmaster of the RPAB Research platform for agricultural biotechnology in the S. Seifullin Kazakh Agro Technical University (Astana, Kazakhstan)
Talgatkyzy N.
researcher, master of Natural Sciences Research platform for agricultural biotechnology in the S. Seifullin Kazakh Agro Technical University (Astana, Kazakhstan)
ASSESSMENT OF DAMAGE TO MACADAMIA NUTS BY PATHOGENIC MICROORGANISMS
Аннотация: this article discusses the problem of damage to the composition of the product and the human body by pathogenic microorganisms and low-active fungi of healthy and expensive macadamia nuts imported to the Republic of Kazakhstan from abroad. The relevance of the study lies in the fact that the damage to food products by microscopic fungi and other microorganisms is caused by the influence of various dangerous pathogenic agents - mycotoxins, which reduce the usefulness of the product, and, on the contrary, is characterized by a very high level of danger for anthropogenic physiology.
Ключевые слова: mycotoxin, pathogenic microorganisms, Penicillium, macadamia, nut, Aspergillus, Mucor.
Contamination of agricultural products with pathogenic microorganisms can occur before or after harvesting the product. Comfortable humidity, comfortable temperature, non-compliance with sanitary conditions during the transportation of products give a great chance for the intensive spread of pathogenic fungi in the
product. Currently, as a result of food pollution, the birth of many food-borne diseases that affect people every year is becoming the main problem of the Health Organization around the world.
Object and methods of research.
The object of the study was a macadamia nut, which was damaged by foreign microorganisms, in the external image of which the phenomenon of rotting was observed.
The following materials were used to carry out the study:
-damaged parts of macadamia nuts,
- Chapek dox Agar nutrient medium,
- Potato glucose Agar,
- Hiss nutrient medium (glucose, mannitol, maltose, sucrose, lactose).
- Amylolytic medium-starch (raw potatoes).
- Proteolytic medium-milk.
The following equipment was used for the study:
-Biosafety box of the 2nd protection class, designed for the separation of pathogenic microorganisms, carrying out sowing and planting of crops in a nutrient medium.
- olimpus bx43 binocular microscopes for detecting pathogenic microorganisms, fungi.
- TS-1/80 SPU thermostat to maintain temperature.
- Autoclave for sterilization of petri dishes and Culture Media.
Research methods:
• Microbiological method (microscopy, planting in a culture medium, identification with Koh solution)
• Biochemical method (determination of saccharolytic, amylolytic, proteolytic, caseinolytic activity)
• Statistical. Microsoft Excel was used to compare the results obtained with each other.
Figure 1. Analysis of the qualitative composition of microorganisms in macadamia nut samples.
As shown in Figure 1, pathogenic fungi were detected in samples M-1.2, M-
2.1, M-2.2, m-3.1, M-4.1, while yeast was detected in samples m-1.1, m-2.2, m-3.1,
3.2, m-4.1. In addition, Calonia of bacteria was observed in almost all, except for the samples M-1.2, M-2.1.
One of the initial parts of the study was that we enlarged the damaged part of the core of the macadamia nut under a microscope with a 10% Con solution X40, x100 times to make sure that there were spores or mycelium.
Figure 2. Affected parts of macadamia nut.
As shown in Figure 2, as a result of the grading of the macadamia nut, kernels are shown that are severely damaged, rot, yellowing and are not suitable for use as food. And all strains were isolated with the help of a scalpel, and research was carried out.
Figure 3. 10% Con solution of the affected part under a microscope view.
Table 1. Identification of pure culture and microorganisms.
М-1.2.
Aspergillus tubingensis
М-3.1
Penicillium spp
Pure culture (KGA) Front, back of the colony
identification (microscopy)
М-2.1
Aspergillus niger
As illustrated in the table above, strains showed an increase in the KGA nutrient medium at 28 °C on the 4th day. In the M-1.2 strain, the pathogenic fungus Aspergillus tubingensis was identified, consisting of a black Spore and pale mycelium. This is due to the fact that one of the features of this fungus has a pronounced tendency to form yellow sclerotia.
To study the biochemistry of new cultures, the hiss culture medium was prepared and planted. The study gave its results on the 3rd day. For the study of Biochemistry, standard indicators of the hiss medium were used mannitol, maltose, lactose, glucose and lactose carbohydrates (Table 2).
Table 2. Results in the study of biochemistry of cultures.
Strain
М-1.2 М-2.1 М-3.1 М-4.1
Glucose - - - +
Lactose + - - +
Mannitol + + + +
Maltose + - + +
Sucrose + + + +
As shown in Table 2, the M-1.2 strain failed to break down all but glucose. And the M-4.1 culture showed increased saccharolytic activity for all carbohydrates. Cultures m-2.1 and M-3.1 did not show the same activity for glucose and lactose, but,
with the same breakdown of sucrose and mannitol, the activity was observed to be higher.
%nMW*M.it»' Jf
kwMffH*«wi«mM|
A B C D
Figure 5. Biochemical activity of strains (A-M-1.2, B- M-2.1, C-M-3.1, D - m-4.1) Caseinolytic activity gave the following results in the determination. The detection
was between 2 days (Figure 6).
H
a b c d
Figure 6. Determination of the caseinolytic activity of pathogenic microorganisms of macadamia nuts in liquid, homemade milk. (a-M-1.2, b-M-2.1, c-M-3.1, d-m-4.1).
As shown in Figure 6, it was found that the strains M-1.2 and M-4.1 have very high caseinolytic activity. As a result, we made sure that in the test tube the microorganism actively reacted to the chemical composition of the milk, coarsened the milk and formed a slimy sediment at the bottom of the test tube. Meanwhile, it has been observed that the caseinolytic activity of strains M-2.1 and M-4.2 is lower compared to the two strains above.
In these strains, it was observed that whey was released from the milk, but could not coarse. In addition, to determine the proteolytic activity of microorganisms
damaging the product, we used ordinary potatoes. And a fairly accurate result was obtained (Figure 7).
a b c d
Figure 7. Results of proteolytic activity of microorganisms (a-M-1.2, b-M-2.1, c - M - 4.1, d-m-3.1).
As a result of Figure 7, it is observed that all microorganisms are damaged by rotting potatoes, forming their spores and parasitizing on the edges. This view is observed from the culture G - M-3.1. In cultures A and B, a black spot fell on the potatoes, and the rotting process developed rapidly. And it was found that the B-4.1 strain covered the surface of the map with a white cotton-like Spore.
As for the results of the study, it was found that macadamia nut as a result of import and storage inconvenience, temperature, humidity is affected by Bacillus bacteria-10%, along with Sona, fungi Aspergillus spp -25%, Penicillium spp - 35%, Penicillium roqueforti-15%, Aspergillus niger 15%. It has been established that the use of the product as food under the influence of pathogenic microorganisms poses a danger to the human body, causes diseases that lead to diarrhea and intestinal diseases.
СПИСОК ЛИТЕРАТУРЫ:
1. Improving the Safety and Quality of Nuts Woodhead Publishing Series in Food Science, Technology and Nutrition 2013, Pages 274-296;
2. FDA Regulations Guidance (2010);
3. BEUCHAT, L.R. (1978), Relationship of water activity to moisture content in nuts Journal of Food Science, 43, 754 - 755;
4. WENKAM, N.S. and MILLER, C.D. (1965), Composition of Hawaii fruits, Hawaii Agricultural Experiment Station Bulletin, No. 135;
5. Institute of Medicine, 2000b, 2001, USDA, 2011
