Arborio rice (Oryza sativa L., japonica group, Long A)

Description
Oryza sativa L. cultivar Arborio is among the most traditional Italian rice varieties used for risotto. It belongs to the japonica group and to the commercial class Long A, historically selected and cultivated in the Po Valley, especially near the town of Arborio (Piedmont), from which it takes its name.

The grain is notable for its large size, semi-round profile and strongly pearled appearance caused by an extended central “pearl” (opaque core of the endosperm). This area, rich in starch, reflects both the internal structure of the grain and its technological behaviour. Arborio is characterised by a moderate–low amylose fraction and a predominant proportion of amylopectin. During cooking, this promotes surface starch release, generating the creamy texture required in Italian risotto recipes. When properly managed (liquid addition, stirring, heat control), Arborio grains can retain a slightly firm core, while still yielding a smooth, cohesive final sauce.

On the agronomic side, Arborio is a medium-late cycle japonica, with a relatively tall plant architecture. This makes it more sensitive to lodging and therefore requires careful crop management (field water levels, nitrogen inputs, sowing density). The kernel, once milled, is normally sold as polished white rice for risotto, typically in vacuum-sealed packs, with average cooking times ranging from 15 to 18 minutes.

Botanical classification
Common name: Arborio rice (medium–large grain rice)
Clade: Angiosperms
Order: Poales
Family: Poaceae
Genus: Oryza
Species: Oryza sativa L.

Cultivation and growth conditions

Climate
Arborio rice is a paddy rice cultivar suited to warm–temperate climates, with hot summers and a good availability of water throughout the growing season. It requires a frost-free vegetative period, with relatively high average temperatures during tillering, stem elongation and ripening. It is sensitive to low temperatures during germination and flowering, which can reduce grain set and yield.

Exposure
Like other paddy rice types, it needs full sun to ensure high photosynthetic activity and good panicle formation. Prolonged shading or competition from tall vegetation at the paddy margins reduces yield and favours the development of weeds.

Soil
Arborio rice is usually grown on flat land suitable for flooding, with clay or clay–loam soils capable of holding water on the surface. Soils with good levels of organic matter and medium to high fertility are preferable. Very sandy, highly permeable soils are unsuitable because they do not allow a stable water layer to be maintained. The optimal pH ranges from slightly acidic to neutral or mildly alkaline.

Irrigation
The crop is managed mainly under flooded conditions. After seedbed preparation (on dry soil or in water, depending on the technique), a constant water layer (a few centimetres) is maintained over the soil for most of the cycle. Careful management of water levels (pre-emergence, tillering, stem elongation, ripening) is essential to control weeds, reduce water stress and ensure uniform growth. Imbalances or unplanned dry periods can cause physiological stress and yield losses.

Temperature
Optimal temperatures for germination are generally above 12–13 °C, while for vegetative growth and flowering values between about 20 and 30 °C are preferable. Too low temperatures at anthesis can impair fertilization; on the other hand, prolonged heat combined with strong radiation and dry winds can cause grain scorching and quality defects (chalkiness, breakage).

Fertilization
Arborio rice needs a balanced supply of nitrogen (N), phosphorus (P) and potassium (K):

• Nitrogen is often split (pre-sowing or pre-flooding, then topdressings) to promote good tillering without excessive lodging.

• Phosphorus supports early root system development and crop establishment.

• Potassium contributes to lodging resistance and improves several technological quality traits of the grain.

Excess nitrogen increases susceptibility to fungal diseases (e.g. blast), raises the risk of lodging and can make the crop more sensitive to other pests.

Crop care
Main crop care operations include:

• weed management through crop rotation, possible false sowing, mechanical control and/or targeted herbicide use;

• accurate land levelling to ensure uniform flooding;

• careful regulation of water levels to limit aquatic weed species and reduce water stress;

• monitoring of diseases (e.g. blast) and pests, applying, where possible, integrated pest management strategies;

• choosing an appropriate sowing density to limit internal competition and the risk of lodging.

Harvesting
Harvest takes place when grain ripening is uniform and grain moisture is suitable for combine harvesting. Excessive delay increases the risk of lodging, shattering and quality loss. After harvest, grain is dried to a moisture content compatible with safe storage and with subsequent processing stages (dehusking, polishing, packing).

Propagation
The Arborio cultivar is propagated using certified seed, produced in varietal seed multiplication plots to ensure genetic purity (grain type, cooking behaviour, technological characteristics). On farm, sowing in paddy fields (broadcast or in rows, on dry soil or in water depending on the system adopted) is carried out, adjusting the seed rate according to target plant density, soil characteristics and planned input levels.

Indicative nutritional values per 100 g

(raw white Arborio rice)

• Energy: ~ 345–355 kcal

• Water: ~ 8–12 g

• Total carbohydrates: ~ 76–81 g

  • starch is the dominant carbohydrate fraction

• Dietary fibre: ~ 0.6–1.8 g

• Proteins: ~ 7–9 g

• Total fats: ~ 0.4–1 g

  • first occurrence SFA (Saturated Fatty Acids): minor share of total lipids; excessive SFA in the diet is linked to higher LDL cholesterol

  • MUFA (MonoUnsaturated Fatty Acids): small proportion

  • PUFA (PolyUnsaturated Fatty Acids): similar or slightly higher than MUFA

• Sodium/salt: negligible, as no salt is naturally present

Composition can vary depending on cultivation area, agricultural season, brand and analytical methods.

Key constituents

• Complex carbohydrates

  • starch (amylose + amylopectin), with moderate–low amylose content favouring creamy behaviour in cooking

• Rice proteins

  • albumins, globulins, prolamins, glutelins in proportions typical of polished white japonica rice

• Lipid fraction (very low overall)

  • minor quantities of SFA, MUFA and PUFA

• Dietary fibre

  • limited amount in white Arborio; higher only in wholegrain variants

• Micronutrients

  • small amounts of B-group vitamins

  • minerals such as phosphorus and magnesium present in modest levels

• Rice phytocomponents

  • phenolics, phytosterols and γ-oryzanol primarily retained in bran layers; therefore strongly reduced in polished Arborio compared to brown rice

Production process

1. Cultivation and harvest

   • sowing of Arborio japonica rice in paddy fields (mainly Northern Italy)

   • management of fertilisation, irrigation and phytosanitary control

   • mechanical harvesting of mature paddy (risone)

2. Drying

   • controlled drying to bring moisture to safe storage levels

3. Cleaning and storage

   • removal of foreign bodies and impurities

   • silo storage with monitoring of humidity, temperature and storage pests

4. Dehusking and milling

   • dehusking to obtain brown rice

   • whitening and polishing to produce white Arborio Long A

   • selection to remove broken kernels and defects

5. Quality control and packaging

   • checks on physical quality, hygiene standards and moisture

   • packaging (often vacuum packed) with indication of variety, origin, cooking time and nutritional data

Physical properties

• Commercial class: Long A rice

• Grain shape: large, semi-round, slightly squared profile

• Endosperm: extended central pearl

• Colour: white (slightly straw-coloured tones possible)

• Raw consistency: firm and mechanically resistant kernel

Sensory and technological properties

• Flavour: neutral, cereal-like, suitable for absorbing stock, seasonings and sauces

• Aroma: delicate, non-aromatic japonica

Cooking behaviour

• strong capacity to absorb liquid

• marked starch release → creamy risotto matrix

• ability to maintain a slightly firm central core with correct cooking

• risk of over-softening if cooking time is exceeded

Technological aspects

• ideal for emulsions and “mantecatura” (butter, oils, cheese)

• good volumetric yield during cooking

• lower hold of individual grains in extended cooking compared to higher-amylose varieties

Food applications

• Traditional Italian risotto (meat, fish, vegetables, cheese)

• single-dish risotto meals with pulses or vegetables

• rice timbales and moulded dishes requiring a creamy base

• soups where controlled starch release is desired

Less suitable for:

• preparations requiring fully separate grains (rice salads, dry side dishes)

• applications needing very high structural stability across reheating cycles (industrial ready meals often prefer varieties with higher amylose content or Long B/indica types)

Nutrition and health

Arborio behaves nutritionally like other polished white japonica rices:

• predominance of complex carbohydrates (starch)

• moderate protein content

• very low total fat with reduced SFA and relatively higher proportions of unsaturated fats (MUFA, PUFA)

• low fibre level in refined form

Dietary considerations:

• energy and lipid impact of a risotto depends mainly on portion size and added fats (butter, cheese, oils, fatty ingredients)

• post-prandial glycaemic response is typical of refined high-starch cereals; portion control and pairing with fibre-rich ingredients, quality fats and proteins can help modulate it

• rice is naturally gluten-free, making Arborio suitable for coeliac diets when cross-contamination is prevented along the supply chain

Portion note

Indicative raw Arborio amounts:

• main course risotto: ~ 70–80 g per person

• moderate portion/side: ~ 50–60 g per person

Portions must be tailored to energy needs, meal structure and presence of other foods.

Allergens and intolerances

• Arborio rice is naturally gluten-free and suitable for coeliacs if handled in facilities that exclude cross-contamination

• rice allergy is possible but uncommon compared to wheat allergy

• low-FODMAP profile relative to several other cereals; digestive tolerance is generally good, with individual variability

• most adverse reactions during consumption tend to derive from added ingredients rather than the rice itself

Storage and shelf-life

For the raw product:

• store in a cool, dry, clean place

• protect from heat, humidity and strong odours

• keep packaging intact, or transfer to airtight containers once opened

• typical shelf-life of packaged white Arborio: around 24 months, depending on storage and producer specifications

For cooked rice:

• cool rapidly if not consumed immediately

• store chilled in a sealed container

• consume within ~24 hours under proper hygienic conditions

Safety and regulatory

• Arborio is a traditional food cereal fully regulated under standard rice-product laws

• subject to controls on:

  • chemical contaminants (e.g. heavy metals, pesticide residues, mycotoxins)

  • microbiological criteria

  • traceability and labelling

• gluten-free claims must comply with legal thresholds and certified production lines

• no extra restrictions apply specifically to Arborio beyond those common to white rice products

Labelling

For Arborio sold as food, labels should include:

• product name (e.g. “Arborio Long A rice”)

• variety (Arborio)

• origin (where required)

• net quantity

• minimum durability date

• storage instructions

• nutritional declaration per 100 g (and where applicable per portion)

• cooking times and intended culinary use may also be stated

• any claims (e.g. “gluten-free”) must be analytically supported and legally compliant

Troubleshooting

In cooking

• excessive stickiness / overly creamy result:
  → reduce cooking time slightly; stir more gently; moderate butter/oil addition

• grain too firm at core:
  → extend cooking by 1–2 minutes and ensure uniform liquid distribution

• broken grains or surface flaking:
  → avoid vigorous stirring; use intact quality kernels; maintain gentle simmer rather than rolling boil

In storage

• insect presence in open containers:
  → reduce storage duration, inspect periodically, keep in sealed jars

• “stale” or foreign odours:
  → isolate from products with strong scents; use airtight, odour-neutral containers

Main INCI functions (cosmetics)

Cosmetic ingredients do not specify the Arborio variety; they are labelled simply under Oryza sativa. Examples include:

• Oryza Sativa (Rice) Starch – absorbent, texturising, mattifying agent

• Oryza Sativa (Rice) Bran Oil – emollient, skin conditioning, lipid-replenishing

• Oryza Sativa (Rice) Extract – can support conditioning effects and contribute minor antioxidant properties

Typical INCI roles:

• skin conditioning

• emollient

• absorbent/opacifying

Conclusion

Arborio rice is one of the benchmark Italian varieties for risotto, belonging to the japonica group and Long A commercial class. Its large semi-round grain, extended pearled core and moderate–low amylose content enable strong starch release in cooking, resulting in the creamy texture that characterises traditional risotto dishes.

Nutritionally, Arborio aligns with other polished white rices: moderate calories, predominant complex carbohydrates, modest proteins, very low total fats and absence of gluten. Diet quality depends mainly on portion size and the nature of the accompanying ingredients.

From a technological standpoint, Arborio is a specialised ingredient ideal for creamy, mantecato preparations, less suitable for dishes that require grain separation. Proper cooking control, storage and packaging enhance its performance, confirming Arborio as a key variety in Italian culinary culture.

Mini-glossary

• Amylose – linear starch component; higher levels support firmer, less sticky grains after cooking.

• Amylopectin – branched starch component; higher levels promote creaminess and starch release.

• Long A – commercial class of rice grains that are long but wider and less slender than Long B/indica types.

• Pearl (of the grain) – opaque central zone of the endosperm related to starch distribution and cooking behaviour.

• SFA – Saturated Fatty Acids: dietary fats that, when consumed in excess, are linked to higher LDL cholesterol.

• MUFA – MonoUnsaturated Fatty Acids: unsaturated fats considered more favourable than SFA when balanced in the diet.

• PUFA – PolyUnsaturated Fatty Acids: include n-6 and n-3 fatty acids, considered beneficial when proportioned appropriately in overall diet.

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).

Rice studies

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

References____________________________________________________________________

(1)  Bidlack W. Phytochemicals as bioacive agents. Lancaster, Basel, Switzerland: Technomic Publishing Co., Inc; 1999. pp. 25–36.

(2) Singh SP, Gruissem W, Bhullar NK.   Single genetic locus improvement of iron, zinc and β-carotene content in rice grains.    Sci Rep. 2017 Jul 31;7(1):6883. doi: 10.1038/s41598-017-07198-5.

Abstract. Nearly half of the world's population obtains its daily calories from rice grains, which lack or have insufficient levels of essential micronutrients. The deficiency of micronutrients vital for normal growth is a global health problem, and iron, zinc and vitamin A deficiencies are the most prevalent ones. We developed rice lines expressing Arabidopsis NICOTIANAMINE SYNTHASE 1 (AtNAS1), bean FERRITIN (PvFERRITIN), bacterial CAROTENE DESATURASE (CRTI) and maize PHYTOENE SYNTHASE (ZmPSY) in a single genetic locus in order to increase iron, zinc and β-carotene content in the rice endosperm. NAS catalyzes the synthesis of nicotianamine (NA), which is a precursor of deoxymugeneic acid (DMA) iron and zinc chelators, and also chelate iron and zinc for long distance transport. FERRITIN provides efficient storage of up to 4500 iron ions. PSY catalyzes the conversion of GGDP to phytoene, and CRTI performs the function of desaturases required for the synthesis of β-carotene from phytoene. All transgenic rice lines have significantly increased β-carotene, iron, and zinc content in the polished rice grains. Our results establish a proof-of-concept for multi-nutrient enrichment of rice grains from a single genetic locus, thus offering a sustainable and effective approach to address different micronutrient deficiencies at once.

(3) Zarei I, Oppel RC, Borresen EC, Brown RJ, Ryan EP. Modulation of plasma and urine metabolome in colorectal cancer survivors consuming rice bran.  Integr Food Nutr Metab. 2019 May;6(3). doi: 10.15761/IFNM.1000252.

Abstract. Rice bran has bioactive phytochemicals with cancer protective actions that involve metabolism by the host and the gut microbiome. Globally, colorectal cancer (CRC) is the third leading cause of cancer-related death and the increased incidence is largely attributed to poor dietary patterns, including low daily fiber intake. A dietary intervention trial was performed to investigate the impact of rice bran consumption on the plasma and urine metabolome of CRC survivors. Nineteen CRC survivors participated in a randomized-controlled trial that included consumption of heat-stabilized rice bran (30 g/day) or a control diet without rice bran for 4 weeks. A fasting plasma and first void of the morning urine sample were analyzed by non-targeted metabolomics using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). After 4 weeks of either rice bran or control diets, 12 plasma and 16 urine metabolites were significantly different between the groups (p≤0.05). Rice bran intake increased relative abundance of plasma mannose (1.373-fold) and beta-citrylglutamate (BCG) (1.593-fold), as well as increased urine N-formylphenylalanine (2.191-fold) and dehydroisoandrosterone sulfate (DHEA-S) (4.488-fold). Diet affected metabolites, such as benzoate, mannose, eicosapentaenoate (20:5n3) (EPA), and N-formylphenylalanine have been previously reported for cancer protection and were identified from the rice bran food metabolome. Nutritional metabolome changes following increased consumption of whole grains such as rice bran warrants continued investigation for colon cancer control and prevention attributes as dietary biomarkers for positive effects are needed to reduce high risk for colorectal cancer recurrence.

Brown DG, Borresen EC, Brown RJ, Ryan EP. Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial. Br J Nutr. 2017 May;117(9):1244-1256. doi: 10.1017/S0007114517001106. 

Abstract. Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B6 metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts.

Beyer P, Al-Babili S, Ye X, Lucca P, Schaub P, Welsch R, Potrykus I. Golden Rice: introducing the beta-carotene biosynthesis pathway into rice endosperm by genetic engineering to defeat vitamin A deficiency. J Nutr. 2002 Mar;132(3):506S-510S. doi: 10.1093/jn/132.3.506S. 

 Abstract. To obtain a functioning provitamin A (beta-carotene) biosynthetic pathway in rice endosperm, we introduced in a single, combined transformation effort the cDNA coding for phytoene synthase (psy) and lycopene beta-cyclase (beta-lcy) both from Narcissus pseudonarcissus and both under the control of the endosperm-specific glutelin promoter together with a bacterial phytoene desaturase (crtI, from Erwinia uredovora under constitutive 35S promoter control). This combination covers the requirements for beta-carotene synthesis and, as hoped, yellow beta-carotene-bearing rice endosperm was obtained in the T(0)-generation. Additional experiments revealed that the presence of beta-lcy was not necessary, because psy and crtI alone were able to drive beta-carotene synthesis as well as the formation of further downstream xanthophylls. Plausible explanations for this finding are that these downstream enzymes are constitutively expressed in rice endosperm or are induced by the transformation, e.g., by enzymatically formed products. Results using N. pseudonarcissus as a model system led to the development of a hypothesis, our present working model, that trans-lycopene or a trans-lycopene derivative acts as an inductor in a kind of feedback mechanism stimulating endogenous carotenogenic genes. Various institutional arrangements for disseminating Golden Rice to research institutes in developing countries also are discussed.