EFFECT OF CRUSHING TIME ON THE QUANTITY AND QUALITY OF MILK YIELD DURING THE PRODUCTION OF PLANT MILK

ABSTRACT

In this article, the effect of processing time on the quantity and quality of milk by the method of wet crushing of plant-based milk is studied in experiments. Kernels of 4 different samples of local almond varieties were selected as the research object. For all samples, the same amount of almond kernels was taken and the same amount of distilled water was added as a solvent. 4 samples were crushed for 5, 10, 15, 20 minutes, respectively. The obtained results were compared in terms of quantity and quality, and organoleptic evaluations were carried out according to the requirements of the GOST standard. The Lactoscan S analyzer analyzes the milk components in the samples, and all the analysis results are presented in the tables. All analyzes are discussed, and the optimal time of crushing when obtaining plant-based milk is presented in the conclusion of the article.

АННОТАЦИЯ

В этой статье исследуется влияние времени измельчения на количество и качество молока при влажном способе измельчения молока на растительной основе в экспериментах. В качестве объекта исследования были выбраны 4 разных образца местных сортов миндаля. Для всех образцов был взят один и тот же сорт и одинаковое количество миндальной муки, и в качестве растворителя было добавлено такое же количество дистиллированной воды. Время измельчения образцов в разное время проводилось в 5, 10, 15, 20 минут. Полученные результаты сравнивали по количеству и качеству, проводили оргонолептические оценки по требованиям ГОСТа. В анализаторе lactoscan s анализируются компоненты молока в образцах, а все результаты анализа представлены в таблицах. Все анализы обсуждаются, а оптимальное время дробления при получении молока на растительной основе приводится в заключительной части статьи.

Keywords: alternative milk, plant substances, extraction, emulsion, ultrasonic, crushing.

Ключевые слова: альтернативное молоко, растительные вещества, экстракция, эмульсия, ультразвук, измельчение.

Introduction. Plant milks require specific parameters and regimes in the production process according to the raw material category. Currently, the production and consumption of plant-based milk alternatives is growing rapidly. It is known from the literature that today all plant milks are obtained on the basis of plant products belonging to 5 categories. They are plant milk based on grain-based (oat, rice, corn, wheat milk), based on legumes (soy, peanut, lupine, pea milk), nut-based (almond, pistachio, nut milks), based on seeds (sunflower, sesame, flax milk), pseudo grains (quinoa, amaranth milk). In the production processes of plant-based milk alternatives, different temperature indicators can be used directly and indirectly according to the functional purpose of the product. [1-2p]

Extracting milk from plants has been known to people in various forms since ancient times, but this branch of food production is not yet a large-scale industry. Taking into account the opportunities of raw materials in Uzbekistan, it is possible to produce competitive products at the world level in this industry, which is expected to develop in the future. Due to its wealth of useful components, technological possibilities for obtaining alternative milk, alternative milk production from almond kernel is one of the developing directions in the world.

All plant milks consist mainly of splitting the plant matter with water and filtering the resulting emulsion to the required size. This seemingly simple process consists of several technological steps. When making milk based on many nuts and legumes, you may encounter technological problems such as unpleasant tastes, smells, and non-combination of plant substances with water. One of the similar problems is to keep the temperature optimal for the raw material throughout the process. Almost all plant milks use crushing devices, and since these devices are made of metal and work quickly, they can heat up the product as well.

There are two main technological methods for the production of plant milk: one is the wet technological process, and the other is the dry technological process. The wet process, which involves soaking and grinding, begins by placing grains, legumes, nuts or seeds in large stainless steel tanks containing filtered water and a small amount of salt. Soaking time varies depending on the level of hydration of the plant, but can last up to 12 hours. The soaking process can remove enzyme inhibitors and improve nutrient digestibility and bioavailability. Softens the plant to aid further processing. After soaking, the grain, legumes, nuts or seeds are washed and drained. Next, they are processed to a smooth puree or paste. [2; 2-p]

Optimum time of dry or wet crushing of plant material is very important in extracting milk from plants. During the experiments, it was noticed that the prolongation of the churning time affects the quantity and taste of alternative milk. In this article, the effects of different temperatures and duration of ripening time on the quantity and quality of almond milk in the process of extracting milk from almonds are described.

Method and materials

1. Preparation of almond milk samples

4 different samples of milk were taken from the kernel of the local "Samarkand" variety, created on the basis of the type of sweet almond (Amygdalus communis L.), which grows under natural conditions in Uzbekistan. For each sample, 50 g of almond kernels were extracted and dried at 50º C for 20 minutes. In order to dissolve the substances in dried almond kernels and form an emulsion, 1/6 of distilled water was allocated for each sample. A household blender SH-BL-03K with a maximum speed of 1200 rpm was used to crush the samples in laboratory conditions. After grinding, the samples were filtered, processed in a D160 laboratory mini-homogenizer for 15 minutes and packed in sterile glass bottles for observation.

2. Determination of organoleptic indicators of samples

The color, taste, smell, and consistency of almond milk were studied based on the standard requirements of GOST 29245-91 during the organoleptic evaluation of the samples. According to the requirements of this standard, the organoleptic indicators of milk (taste and smell, structure, color) are determined depending on the method of consumption of this product. The temperature of the analyzed products should be between 15 and 20°C.^[1] The color of the samples was determined by pouring them into a glass container in natural light. Smell detection - milk samples were strained in a closed container and, after shaking, were identified by smell when opening the lid of the container. The taste of the sample was determined by shaking the milk well and drinking it. Consistency was determined by pouring milk from one bottle to another. When determining the consistency, it is important that the milk is not stretchy, does not settle and is homogeneous. [3; 2-p]

3. Analyses performed on the analyzer

"Lactoscan S" milk analyzer was used to determine some parameters of the obtained samples. This milk analyzer calculates analyzes based on components that depend on the freezing point. The freezing point depends only on the dissolved components in the milk and the amount of water used as a solvent. The Lactoscan S analyzer complies with the requirements of the GOST 26809-86 standard and works on the basis of ultrasonic technology.

Results. All almond milk samples were mixed with the same amount of distilled water, and the mixing time was 5 minutes each, in a household blender and passed through a homogeneous filter. Sample 1 5 minutes at 1200 rpm. and sample 4 was crushed at the same speed for 20 minutes. It was found that 5 minutes is not enough to grind almond kernels, it was seen that the shell of the kernel does not separate, and the mass is not completely emulsified. It was found that a longer crushning time affects the amount of milk after the emulsion is filtered. When the crushing time was long, almond substances formed a slimy mass and more mass remained in the filtrate. Quantitative results are presented in Table 1.

Table 1.

Effect of crushing time on the amount of milk

The organoleptic results of the experiment were studied based on the requirements for the organoleptic evaluation of milk and milk products according to the GOST standard. Organoleptic evaluations were carried out 30 minutes after the samples were ready, after all the samples had cooled and reached a uniform temperature. The increase in temperature also affected the organoleptic parameters of almond milk, as the prolongation of the crushing time caused the emulsion to heat up. The results of organoleptic evaluations are presented in Table 2.

Table 2.

Orgonoleptic indicators of experimental samples of milk obtained on the basis of almond kernel

After straining the samples at room temperature for 5 minutes, they were analyzed in the "Lactoscan S" milk analyzer. The error of the analyzer is on average ± 0.30% for all indicators. The indicators analyzed in the analyzer are presented in Table 3.

Table 3.

Analyzes performed on the Lactoscan S analyzer

Discussion. As can be seen from the results, the influence of the crushing time on the quantity and quality of the obtained milk is significant. In general, the parameters of the second sample can be accepted as the optimal variant of the experiment. After the second sample was filtered for 10 minutes, 310 ml of milk was obtained. A relatively drier mass of almond kernel and other solids remains in the filtrate. The analyzes obtained in the analyzer also showed that 10 minutes of crushing time is enough for the necessary components of almond kernel to dissolve in water. The indicators of the first sample showed that 5 minutes was not enough for crushing. Since the almond kernels crushed for 5 minutes were not completely broken down, the components of the kernels did not have time to go into the emulsion, and the density was also low. The longer the crushing time, the more the breakdown of the tissues in the kernel increases, and the amount of tissues passed into the milk also increases. The fourth sample was crushed for 20 minutes and a minimum amount of 140 ml of milk was obtained. In the fourth sample, the higher temperature generated during prolonged crushing and heavy friction caused the crushed plant matter to turn into a slimy slurry.

In organoleptic analysis, it can be seen that the prolongation of the crushing time had a negative effect on the taste and smell of almond milk. Such differences can be said to be related to the texture of the almond kernel. The results of the organoleptic analysis presented in Table 2 also proved that the first sample is optimal.

Conclusion. In conclusion, the indicators of the second sample can be called the optimal option. The reason for this is not only the quantity, but also the fact that the main components of almond kernel remain in milk in relatively large quantities. In the third and fourth samples, the components were separated due to the longer grinding time, but the increase in temperature and the prolonged grinding process turned the emulsion into a slimy slurry. This requires additional chemical and technological processes.

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