Instructions on a packet of rice suggest serving 75 g per person. Yuang carefully weighed out 75 g of rice and counted 2896 grains of rice. Work out the average (mean) mass of a single grain of rice. Give your answer correct to three significant figures (3 s.f.).
Answers
Answer:
Both white and brown rice contain mainly carbohydrate and some protein, with virtually no fat or sugar.
Cooked rice contains a lot of water, making up almost 70% of its total weight.
White and brown rice have similar calorie, carbohydrate, protein, and fat content. A 100 gram (g) serving of white, short-grain, cooked rice contains the following nutrients:
Nutrient Amount % Daily Value (DV)
Calories 130
Carbohydrate 28.7 grams (g) 10%
Protein 2.36 g 5%
Fat 0.19 g 0%
Carbohydrate
Rice is primarily composed of carbohydrate, which makes up almost 80% of its total dry weight.
Most of the carbohydrate in rice is starch. Starch is the most common form of carbohydrate in foods.
Starch is made up of long chains of glucose called amylose and amylopectin. Different types of rice have varying amounts of these compounds, which affects the texture of the rice:
Basmati rice is rich in amylose, meaning it does not stick together after cooking.
Sticky rice, or glutinous rice, is low in amylose and high in amylopectin, making it sticky after cooking. This makes it ideal for risottos, rice pudding, and eating with chopsticks.
These compounds also affect how easily the body can digest the rice.
The body takes longer to digest high-amylose rice because the amylose slows down starch digestion. In contrast, the body digests sticky rice very easily.
While many people find sticky rice more palatable, quick digestion can lead to unhealthful spikes in blood sugar levels, especially in people with diabetes.
Fiber
Brown rice contains a higher amount of dietary fiber than white rice — 1.6 g per 100 g. During the processing of white rice, the grain loses the bran, or seed coat, which contains most of the fiber.
The bran contains mainly insoluble fibers, such as hemicellulose, and virtually no soluble fiber.
White and brown rice contain varying amounts of a soluble fiber called resistant starch.
Resistant starch increases butyrate in the gut. Butyrate boosts gut health by reducing inflammation, improving gut barrier function, and reducing the risk of colon cancer.