Globally, rice is the second most productive cereal crop. It is grown in many parts of the world, but mainly in Asia. It accounts for more than 50% of the world\'s staple foods and provides up to 70% of the dietary energy and protein requirements of the daily diet of about 2.5 billion people in Asia. Basmati Rice is not only the staple food of Pakistan but also an important source of foreign exchange earning one-third of the production exported every year.

Rice is considered one of the best of all grains due to its nutritional properties. It has a higher ratio of digestibility, biological value, and protein efficiency with a higher percentage of lysine than wheat. Trace minerals, such as calcium, magnesium, phosphorus, and silicon, and trace amounts of iron, zinc, copper, and manganese.

In addition to cereals, rice bran is incorporated into a variety of food products due to its overall composition, nutritional content, functional properties, and apparent hypoallergenic, which are particularly beneficial for those who exhibit grain allergies. Baked goods offer one of the most promising possibilities for the use of rice bran in food. Rice bran is recommended for bread, muffins, pancakes, cookies, cakes, pies, puffed snacks, and breakfast cereals.

In Southeast Asia, most consumers prefer rice grains that become puffy when cooked and retain their shape without lumps. Generally, two types of rice are mainly grown. Coarse varieties are unscented, while fine varieties are aromatic in nature. Freshly harvested rice develops hardness after cooking. Aging is a great cure.

Freshly harvested rice cooks harder, expels more solids during cooking, and swells less than older rice. Due to the number of physicochemical changes in grain, cooking properties can change significantly in the months following harvest. Storage is an inevitable step that leads to loss of consistency, bulk, and fine texture of rice. Old rice usually costs 25-30% more than fresh rice.

Storage-induced changes in the physicochemical properties of rice may or may not be desirable depending on storage conditions, varieties, and end-user needs. Moisture content, storage temperature, and storage time are important factors affecting the chemical, physical and functional properties of rice during post-harvest storage.

Overall variation may depend on variety, storage conditions, and further processing; however, it is generally accepted that aging rice improves its eating quality. The rate and nature of the conversion are largely dependent on temperature, which catalyzes enzymatic reactions involving starch, proteins, and lipids. Mass change usually occurs rapidly with increasing temperature and storage time. Considering the importance of rice quality, the project plans to evaluate the effects of different storage temperatures and intervals on the chemical, culinary and organoleptic characteristics of high-quality Basmati rice varieties, which will ultimately improve quality. and will lead to improved export recognition. Promote the market.

Chemical Analysis

Moisture content

Moisture plays an important role in determining the quality of rice. High moisture content increases microbial degradation and spoilage during storage. Moisture content is significantly affected by different storage temperatures and periods. From the results, it is clear that there is a significant difference between Basmati Super and Basmati 385. As the temperature increases, the moisture content gradually decreases. The mean moisture content was highest at T5°C, followed by T25°C, and the lowest value was observed at T45°C. Similarly, the moisture content of high-quality rice varieties decreased gradually during the 16-week storage period.

Amylose content

Amylose content is an important parameter that determines the cooking and eating properties of rice. Amylose content of elite rice cultivars showed significant effects due to different treatments of temperature and storage interval. The results showed a significant difference in the amylose content of Basmati Super and Basmati 385.

The amount of both types of amylose decreased with increasing temperature. The mean value of amylose was highest at T5°C and lowest at T45°C. From the beginning of the study to the 16th week, the long-storage amylose content of the high-quality rice varieties gradually decreased.

Alkali spreading value

This is an indirect method of determining the gelatinization temperature, which is the temperature range at which starch begins to expand irreversibly while losing crystallinity in hot water. The lower the alkalinity value, the higher the gelatinization temperature. Different temperature treatments and storage intervals had significant effects on the alkali partition value of high rice varieties.

Basmati Super and Basmati 385 averaged 4.27 and 3.75 respectively. With increasing temperature, the alkali dispersion value of the species decreased gradually. The average value of alkali distribution value is highest at T5℃ and lowest at T45℃. Similarly, alkali partition values ​​of rice varieties also decreased with an increase in storage time.

Cooking Quality

Water absorption ratio

Water absorption is an important factor in judging the cooking quality of rice. Different treatments and storage intervals had significant effects on the water absorption of the two rice cultivars. The results showed a significant difference in water absorption between Basmati Super and Basmati 385.

The water absorption of the two elite types increased gradually with increasing temperature. The average water absorption is lowest at T5℃, highest at T35℃, and the difference is not significant at T45℃. Similarly, water absorption of higher rice varieties also increased with storage time.

Volume expansion ratio

The rate of expansion of rice varieties was significantly affected by handling and storage. The results show that there is a significant difference in the rate of volume expansion of Basmati Super and Basmati 385. Volume averaging shows that the volume expansion ratio of both types increases gradually with increasing temperature. It is lowest at T5°C and highest at T45°C. The rate of volume expansion of milled rice varieties also increased with storage time.

Elongation ratio

Elongation is an important indicator for determining the cooking and eating quality of rice. Elongation is significantly affected by temperature treatment and storage periods. There is a significant difference in the length of the different varieties. Basmati Super and Basmati 385 averaged 2.29 and 2.15 respectively. This method shows that the elongation of both species increases with increasing temperature. The average value of elongation is lowest at T5°C and highest at T45°C.

Sensory evaluation

Sensory evaluation is usually done at the end of product development. This is done to understand how reviewers are reacting to the product and rank their preferences accordingly.