5 DE agosto DE 2013
The nutritional value of fruit juice lies in its ability to provide nutrients and bioactive compounds that favor good health and prevent disease.
Juice as part of a healthy and safe diet
Good health is achieved through a varied and balanced diet that is low in fat and high in carbohydrates, fruits and vegetables, and through regular exercise. Commercial juices offer benefits in terms of the safety and nutrition. Under the 5 A Day program, one of the five recommended servings of fruit and vegetables may come from bottled juice, since it retains the nutritional characteristics of the fruit from which it is made.
Micro- and macronutrients
Fruit juices contain macronutrients (which are needed in greater quantities), such as proteins, carbohydrates and lipids, and micronutrients (which, though also fundamental for the body, are needed in smaller quantities), which include vitamins, minerals, and essential fatty and amino acids.
As is the case with most foods, water is the primary component in fruit juice, accounting for around 90% of total weight. The remainder is soluble solids. In the case of milk, water accounts for 88%, and in vegetables, water content often exceeds 90%.
Drinking juice is one of the most balanced and complete ways to stay hydrated, from a nutritional standpoint.
Carbohydrates, specifically sugars, account for 75-85% of the total soluble solids in fruit juices. These sugars can be divided into two groups: monosaccharides (fructose and glucose) and disaccharides (sucrose).
The proportion of each sugar varies depending on the type of fruit, allowing for a range of uses. For example, when a person needs an immediate energy boost, the ideal juice is grape (rich in monosaccharides), whereas a person who has to watch their blood sugar level should drink apple or pear juice (high in fructose, a sugar with strong sweetening power which is metabolized slower). Orange juice has a slightly higher sucrose content, while pineapple juice is almost completely sugar; as a result, consuming 200 ml daily of any juice would fulfill the recommended calorie intake, provided that no other part of the diet includes sugar in excess quantities.
Bioactive compounds form part of certain foods, such as commercial fruit juices, and have health benefits such as protecting cells from damage caused by oxidation and free radicals.
This category of commercial fruit juices includes important micronutrients which are rich in vitamin C (antioxidant vitamins), provitamin A (beta-carotene), vitamin B9, and several phenolic compounds.
Citrus fruit juices are an important source of certain vitamins; vitamin C is the most predominant and has notable antioxidant properties.
Vitamin C protects the immune system, prevents cardiovascular disease, fights cancer and protects against damage caused by ozone damage and cigarette smoke.
The recommended dose of vitamin C is currently around 80 mg/day (depending on a person's physiological aptitudes), which many fruits contain in just 100 grams.
Vitamin C content varies depending on the fruit; for example, commercial orange juice has 30.1-46 mg/100ml, tomato juice has 8-67.7 mg/100ml, and pineapple juice has 8-58 mg/100ml. The average amount of vitamin C in Spanish juices oscillates between 15 and 75 mg/100g.
Other juices with high vitamin C content include acerola, redcurrant, guava, mandarin, lemon and grapefruit, as well as tomato, strawberry and kiwi.
Carotenoids (beta-carotene is the most common) provide protection against cardiovascular illnesses, high blood pressure, atherosclerosis, cancer and diabetes.
As for provitamin A (beta-carotene), tomato juice has 182-630 µg/100 ml, and peach juice has 180 µg/100ml.
Apricot, persimmon and orange juice also contain carotenoids.
Flavonoids and anthocyanins have special protective properties:
Flavonoids are anti-thrombogenic, anti-inflammatory, anti-tumor, anti-viral heart protectors. They can be found in the following juices: apple, pair, apricot, peach, cranberry, cherry, plum, pomegranate, persimmon, raspberry and grape.
Anthocyanins are natural pigments which give many commercial fruit juices their red, blue and purple color. These compounds are valuable for two reasons: they offer a plethora of physiological effects, mainly by protecting against cardiovascular diseases, and they also have anti-tumor and anti-mutagenic effects, which provide protection against diabetes and neurodegenerative diseases.
We benefit from these properties through grape (especially red) and red berry juices.