Rice (Oryza sativa) is a cereal grain belonging to the family Poaceae and is one of the most widely consumed staple foods in the world. The grain is composed of several layers: outer coverings (hull and bran), germ and starchy endosperm. Depending on the degree of milling, we distinguish brown (whole) rice, which retains bran and germ, semi-milled rice and white rice, which is more polished but lower in fiber than whole rice. There are many varieties and types (short-, medium- and long-grain, aromatic rice, risotto rice, sushi rice, parboiled, etc.), each with specific technological and culinary properties.
As a food ingredient, rice is appreciated for its mild flavor, good digestibility and great versatility. It is a source of complex carbohydrates, provides a certain amount of plant protein and, in the case of brown rice, also dietary fiber, B-group vitamins and minerals such as magnesium and phosphorus. In cooking, it is used in a wide range of dishes: risottos, soups, rice salads, sushi, one-pot meals with vegetables, legumes, meat or fish, as well as for producing rice flour, plant-based drinks, desserts, creams and baby foods. Rice is naturally gluten-free, which makes it suitable for people with coeliac disease or gluten intolerance.
The genus Oryza has many species, here some of the best known:
- Oryza sativa, white rice grown all over the world
- Oryza glaberrima, cultivated in Africa
- Oryza officinalis, cultivated in Vietnam
- Oryza australiensis, cultivated in Australia
- Oryza rhizomatis
- etc.
Italy is the first European producer with crops in the provinces of Vercelli, Novara, Pavia, Biella, Milan, Lodi and others.
The varieties of rice are numerous, over 100,000 and each has different taste and cooking times.
Description
Hulled and milled/whitened cereal (husk, bran, and germ removed), with the kernel composed mostly of starch.
Types: long-grain (indica), medium/long A, and short-grain (japonica); parboiled variants (partial starch gelatinization) and enriched/fortified versions in some markets.
Sensory profile: mild flavor; textures range from fluffy and separate (higher amylose) to sticky (higher amylopectin).
Botanical classification
Common name: rice
Main botanical name: Oryza sativa (cultivated rice; includes japonica and indica groups and other varietal groups)
Family: Poaceae (Gramineae)
Origin: Tropical and subtropical regions of Asia; now cultivated worldwide, from tropical lowlands to temperate irrigated areas
General features: Annual grass with erect, hollow culms, linear leaves and a branched panicle bearing the grains (caryopses). Many varieties are adapted to flooded paddy fields, while others are grown under aerobic or intermittently flooded conditions.
Cultivation and growing conditions
Climate
Typically a warm, humid crop, although many varieties are adapted to cooler temperate environments (e.g. northern Italian rice areas).
Optimal growth temperatures are generally between 20 and 30 °C.
Requires a frost-free growing season of at least 4–5 months with mild temperatures.
Highly sensitive to prolonged cold: low temperatures reduce tillering, flowering and grain filling.
Exposure
Requires full sun throughout the growing period; shading markedly reduces photosynthesis and yield.
Paddy fields are usually located in open, flat areas to allow uniform water distribution.
Wind protection is useful at maturity to limit lodging.
Soil
Well suited to loam or clay–loam soils that can hold water, often with a less permeable horizon that favours surface flooding.
For paddy cultivation, soils with moderate permeability are preferred so that a shallow water layer can be maintained with limited losses.
Optimal pH is generally slightly acidic to neutral (around 5.5–7), though many varieties tolerate slightly more acidic conditions.
Good organic matter and well-managed structure support fertility, water-holding capacity and efficient nutrient use.
Irrigation and flooding
Traditionally grown under continuous flooding:
fields are levelled and surrounded by small bunds,
a shallow water layer (a few centimetres) is kept for much of the cycle, from tillering to late grain-filling.
Flooding helps to:
suppress many weeds,
stabilise soil temperature,
favour certain nutrient dynamics (especially nitrogen) and support high yields.
Increasingly, intermittent flooding and water-saving systems (alternate wetting and drying, delayed flooding, dry seeding with later flooding) are used to reduce water use and environmental impacts while maintaining yield.
Adequate water supply is crucial in key stages: emergence/early growth, tillering, panicle initiation (booting) and flowering.
Temperature
Optimal germination around 18–25 °C.
Best vegetative growth and tillering between 20 and 30 °C.
Flowering and grain filling are very sensitive to extremes:
cold during flowering can reduce pollination and cause empty grains,
excessive heat and surface drying can damage pollen and reduce grain number and weight.
Fertilization
Rice is nutrient-demanding, especially for nitrogen:
nitrogen supports tillering and canopy development, but excessive rates cause lodging and higher disease pressure,
phosphorus is important for root growth, early vigour and uniform panicle formation,
potassium improves resistance to lodging, diseases and abiotic stress and contributes to grain quality.
Nutrient management often combines organic inputs (incorporated crop residues, manure, compost) with mineral fertilizers.
Nitrogen is commonly split into several applications (basal, tillering, sometimes panicle initiation) to match crop demand.
Micronutrient deficiencies (e.g. zinc, iron) may occur in some soils and must be corrected based on soil and plant diagnostics.
Crop care
A well-prepared seedbed (ploughing, puddling/levelling, fine soil tilth) is essential for uniform emergence and for water management.
Weed control is critical, especially in the early stages:
water management (timely flooding),
crop rotation,
where necessary, selective herbicides or mechanical weeding.
Efficient networks of canals and drains are needed to distribute and remove water, maintaining appropriate levels and avoiding excessive ponding in border areas.
Regular monitoring of insect pests and diseases (fungal and bacterial) is required, with preference for integrated pest management and environmentally friendly practices.
Harvest
Harvest takes place when panicles reach physiological maturity and grain moisture has declined to levels suitable for cutting and threshing (often around 20–24%, later reduced by drying).
Modern harvest is mainly mechanised with rice combines capable of working on moist fields.
Early harvest reduces yield and quality (immature grains, more breakage during milling), while late harvest increases risks of lodging, pre-harvest sprouting and grain losses.
After harvest, rough rice is dried, stored and subsequently milled (dehusking, whitening, optional parboiling, etc.).
Propagation and planting
Propagated by seed.
Depending on the system, rice can be:
direct-seeded in flooded fields (broadcast or in rows),
direct-seeded on dry soil with later flooding,
transplanted from nurseries (seedlings raised in wet or dry beds).
Variety choice considers growth duration (early, medium, late), climatic requirements, lodging and disease resistance, grain type (short, medium or long; translucent or chalky) and intended use (table rice, parboiled, sushi, specialty types).
Caloric value (per 100 g)
Raw: ~350–365 kcal; carbohydrate ~77–80 g, protein ~6–8 g, fat ~0.5–1.0 g, fiber low.
Cooked (absorption or excess-water methods): ~120–140 kcal (varies with hydration).
Sodium naturally low; added salt comes from cooking/seasoning.
Key constituents
Starch: the amylose/amylopectin ratio governs stickiness/firmness.
Proteins (mainly glutelins; lysine is limiting); fiber is very low due to milling.
B vitamins and minerals are reduced by whitening; fortified products may add B1, B3, iron, etc.
Inorganic arsenic: generally lower than in brown rice but location- and process-dependent.
Production process
Dehulling (husk removal) → milling/polishing (bran/germ removal) → screening and grading (whole vs broken) → optional parboiling (soak–steam–dry) → packaging under GMP/HACCP.
Optional fortification step; routine controls for moisture, varietal purity, metals/pesticides.
Sensory and technological properties
Gelatinization ~68–78 °C; water uptake typically 2–3× dry weight.
Retrogradation on cooling increases resistant starch (RS), affecting texture and glycemic response.
High-amylose rice yields separate grains (pilaf), while low-amylose favors adhesion (sushi).
Parboiled rice: firmer, less sticky, better hot-hold performance.
Food uses
Side dishes, risotti (Italian japonica types), pilaf, paella, sushi, soups, desserts (puddings), plus rice flours and rice noodles.
Typical water ratio: 1 part rice to 1.5–2.2 parts water (variety and method dependent).
Nutrition and health
Source of carbohydrates with GI from medium to high, modulated by cooling (raises RS), parboiling, higher-amylose varieties, and by adding fat/protein to the meal.
Naturally gluten-free (suitable for a gluten-free diet with cross-contact controls).
Arsenic: rinsing and cooking in excess water with draining can reduce part of the content; prefer suppliers/regions with low As.
Sodium low; fat and sugars negligible.
Lipid profile
Very low total fat; only trace amounts of SFA, MUFA, and PUFA with no meaningful nutritional impact.
Health note: a relatively higher share of MUFA/PUFA vs SFA is generally favorable/neutral for blood lipids, but the effect is not material in white rice.
Quality and specifications (typical topics)
Moisture (target 13–14%), broken percentage, kernel length/shape, degree of milling, chalkiness/whiteness, foreign matter.
Apparent amylose, pasting/viscosity profile, cooking yield.
Pesticides/metals (focus on As), mycotoxins (proper storage), foreign bodies.
For ready-to-eat: compliant microbiology and pH/aw.
Storage and shelf-life
Store cool and dry, protected from odors and infestation; keep sealed or under controlled atmosphere.
Typical shelf-life 24–36 months (white rice); apply FIFO.
Cooked rice is perishable: cool rapidly and hold <4 °C to prevent Bacillus cereus growth.
Allergens and safety
Rice is not a major EU allergen; individual sensitivities are rare.
Risk of gluten cross-contact in mixed mills/lines—verify certifications.
Manage CCP for foreign matter, pests, storage moisture, and hygiene.
INCI functions in cosmetics
Related materials: Oryza Sativa (Rice) Starch, Oryza Sativa (Rice) Bran Extract/Oil (from bran, not present in white rice), Hydrolyzed Rice Protein; functions absorbent/emollient/conditioning.
Troubleshooting
Overly sticky grains: rinse until water runs nearly clear; lower water ratio or use higher-amylose varieties.
Mushy/broken grains: excess agitation or overcooking; choose lower broken grade, control time.
Flat taste: light toasting, use stock instead of water, rest 5–10 minutes after cooking.
Hard core: increase water or time; for pilaf ensure proper toasting.
Insects/off-odors: improve barriers and warehouse sanitation; use traps or modified atmospheres.
Sustainability and supply chain
Traditional flooded paddies can produce CH₄ emissions and require water; practices like AWD (alternate wetting and drying) and efficient varieties can reduce impact.
Upcycling: broken rice → rice flour; bran/germ → rice oil.
Manage processing effluents to BOD/COD targets; use recyclable packaging; full traceability under GMP/HACCP.
Conclusion
Rice is a neutral, versatile ingredient with predictable technological behavior. Varietal choice, amylose/amylopectin balance, and controlled cooking deliver textures and yields suited to a wide range of applications while keeping a simple, adjustable nutritional profile.
Mini-glossary
GI — Glycemic index: blood-glucose response; medium–high for white rice, reducible via RS, parboiling, and meal composition.
RS — Resistant starch: undigested starch fraction; increases with cooling/storage of cooked rice.
SFA — Saturated fatty acids: excessive intake may raise LDL; trace in white rice.
MUFA — Monounsaturated fatty acids (e.g., oleic): generally favorable/neutral; trace in white rice.
PUFA — Polyunsaturated fatty acids (n-6/n-3): beneficial when balanced; trace in white rice.
TFA — Trans fatty acids: avoid industrial TFA; not relevant to dry rice.
ALA — Alpha-linolenic acid (n-3): precursor of EPA/DHA; irrelevant in white rice.
EPA/DHA — Long-chain n-3 fatty acids: present in fish, absent in rice.
MCT — Medium-chain triglycerides: not characteristic of rice.
GMP/HACCP — Good Manufacturing Practice / Hazard Analysis and Critical Control Points: hygiene and preventive-safety systems with defined CCP.
BOD/COD — Biochemical/Chemical oxygen demand: indicators of effluent impact.
FIFO — First in, first out: inventory rotation using the oldest lots first.
Studies
In general, rice contains more than 100 bioactive substances mainly in its bran layer including phytic acid, isovitexin, gamma-oryzanol, phytosterols, octacosanol, squalene, gamma-aminobutyric acid, tocopherol and derived from tocotrienol (1), antioxidants.
It does not contain beta carotene (provitamin A) and has a very low iron and zinc content (2).
In rice bran there are bioactive phytochemicals that exert protective actions against cancer that involve the metabolism of the host and the intestinal microbiome. A diet based on rice bran has shown positive effects in reducing the risk of colon cancer (3).
Allergies: Be careful, rice contains a certain amount of lactose.
The most common types of rice used are :
- Arborio : large grains, the most common in Italy
- Ribe : elongated grains.
- Thaibonnet : medium, elongated and fine grains
- Rome : large grains
- Basmati : thin and elongated grains. Grown in Pakistan and India
- Carnaroli : large grains
- Vialone nano : large, round grains
- Original or Balilla : small round grains
- Jasmine : fine grains of Asian origin
- Red : red, small and narrow grains
- Wild : Zizania palustris
- Baldo : large, shiny grains
- Ganges : from India
- Footboard : releases a lot of starch
- Venus : from China and the Po Valley
- Patna : from Thailand. Long and narrow grains
- Sant'Andrea : Thick and long grains. Releases a lot of starch
Rice viruses and pests: Pseudomonas aeruginosa, Rice yellow mottle virus, Magnaporthe oryzae , Rice Tungro Bacilliform Virus , Lissorhoptrus oryzophilus Kuschel, Oebalus pugnax, Xanthomonas oryzae
