San Marzano tomatoes

Description
San Marzano tomatoes are a prized variety of Solanum lycopersicum (family Solanaceae), traditionally grown in the Agro Sarnese-Nocerino area of Campania (southern Italy). They are characterized by elongated, cylindrical fruits with thin skin, dense flesh, few seeds and a sweet, well-balanced acidic taste. In the PDO (Protected Designation of Origin) form they represent an icon of the Italian tomato-processing tradition, especially for sauces and canned whole peeled tomatoes.

Indicative nutritional values per 100 g (fresh or canned in juice)

• Energy: 18–25 kcal

• Water: ≈ 90–92%

• Carbohydrates: 3–4.5 g

  • of which sugars: 3–4.3 g

• Protein: 0.8–1.3 g

• Total fat: 0.1–0.2 g

  • SFA (saturated fatty acids; excess intake may negatively affect cardiovascular health): traces

  • MUFA (monounsaturated fatty acids, generally considered heart-friendly): traces

  • PUFA (polyunsaturated fatty acids, involved in cellular and metabolic functions): traces

• Dietary fibre: 1–2 g

• Vitamin C: 10–20 mg

• Provitamin A (β-carotene): 100–250 µg

• Potassium: 230–260 mg

Values may vary according to cultivar, cultivation conditions, ripeness and processing (fresh vs canned).

Key constituents

• Carotenoids: high lycopene content, β-carotene, lutein

• Vitamins: vitamin C, provitamin A, small amounts of B-group vitamins

• Minerals: potassium (predominant), magnesium, phosphorus, traces of calcium and iron

• Phenolic compounds: chlorogenic acid, rutin, quercetin derivatives

• Dietary fibre: pectins, hemicelluloses, cellulose

• Natural sugars: glucose and fructose

• Organic acids: citric and malic acids

• Minor volatile compounds responsible for the characteristic tomato aroma

Production process
(Fresh product)

• Varietal selection of authentic San Marzano lines (and, for PDO, specific approved lines)

• Transplanting and cultivation in suitable soils, often of volcanic origin, well-drained and fertile

• Irrigation management and integrated pest management to reduce chemical inputs

• Manual harvesting in several passes, selecting fully ripe fruits

• Sorting and packing for the fresh market

(For processing – peeled / canned San Marzano)

• Reception and sorting of fresh tomatoes

• Washing and removal of defective fruits

• Blanching to loosen the skin

• Peeling (mechanical and/or manual)

• Filling of cans or jars with whole tomatoes and tomato juice

• Sealing and heat treatment (pasteurisation/sterilisation)

• Cooling, batch coding and storage until distribution

Physical properties

• Shape: elongated, cylindrical to slightly prismatic

• Length: typically 6–8 cm

• Skin: thin, easily removable

• Flesh: firm, rich in dry matter, low free water

• Seeds: relatively few and small

• Colour: uniform deep red when ripe

• pH: about 4.2–4.5

Sensory and technological properties

• Flavour: sweet, aromatic, with balanced acidity

• Aroma: intense, fruity and characteristic of traditional Italian tomato sauces

• Texture: compact, meaty pulp, little watery exudate

• Technological behaviour:

  • excellent performance in long-cooked sauces and reductions

  • good shape retention during cooking

  • naturally high consistency thanks to dry matter and pectins

  • limited separation of water in sauces

Food uses

• Fresh consumption (salads, bruschetta, traditional Italian dishes)

• High-quality tomato sauces and ragù

• Neapolitan-style pizza topping and other Mediterranean preparations

• Oven- or pan-roasted tomatoes and confit preparations

• Industrial and artisanal processing into whole peeled tomatoes, fillets and passata/purée

• Premium “gourmet” products labelled as San Marzano or San Marzano PDO

Nutrition & health

• High lycopene content provides antioxidant activity that supports cellular protection and may contribute to cardiovascular health.

• Low energy density and good micronutrient density make San Marzano tomatoes suitable for weight-management diets.

• Dietary fibre supports digestive health and contributes to satiety.

• Potassium helps maintain normal blood pressure and fluid balance.

• Thermal processing (as in canned products) increases lycopene bioavailability compared with raw tomato, while only moderately reducing heat-sensitive vitamin C.

Portion note
A reasonable portion is 100–150 g, equivalent to 1–2 medium San Marzano tomatoes (fresh) or about ½ can of a standard canned product.

Allergens and intolerances

• Naturally free from the main allergens listed in EU legislation.

• Belong to the Solanaceae family; individuals sensitive to this botanical family may experience reactions.

• May be poorly tolerated by people with histamine intolerance, especially in processed or long-stored products.

Storage and shelf-life

Fresh San Marzano tomatoes

• At cool room temperature: about 3–5 days.

• In the refrigerator: up to 7–10 days, with potential loss of aroma and slight texture changes.

Canned / jarred San Marzano tomatoes

• Unopened, at ambient temperature and away from heat and light: 24–36 months (according to label).

• Once opened: transfer from metal to glass or food-grade container, refrigerate and consume within 2–3 days.

Safety and regulatory aspects

• Fresh product must comply with EU marketing standards for fruit and vegetables (size, quality class, integrity).

• Pesticide residues must remain below MRL (Maximum Residue Levels) established by EU legislation.

• Processing plants must operate under GMP and HACCP systems to ensure hygiene and food safety.

• Packaging materials must be suitable for food contact and compliant with EU regulations.

• For San Marzano PDO, cultivation and processing must fully comply with the official PDO specification and are subject to third-party controls and certification.

Labelling

• Name: typically “San Marzano tomatoes” or, for certified product, “Pomodoro San Marzano dell’Agro Sarnese-Nocerino PDO”.

• Country (and, where applicable, specific area) of origin.

• For PDO: PDO logo and mandatory mentions according to the specification.

• Net weight and, for canned products, drained weight.

• List of ingredients (for processed products): tomatoes, tomato juice, possible acidity regulator (e.g. citric acid), and salt if used.

• Lot identification and best-before date.

Troubleshooting

• Excessive water separation in sauces

  • Possible causes: fruits not true-to-type, low dry matter, or improper processing.

• Weak flavour or aroma

  • Possible causes: unsuitable soil/climate, over-irrigation, or premature harvesting.

• Too strong acidity

  • Possible causes: insufficient ripeness, high organic acid content.

• Pulp disintegrates during cooking

  • Possible causes: excessive cooking intensity or non-authentic variety with lower structural integrity.

• Metallic off-flavour after opening cans

  • Possible causes: prolonged storage of product in an opened metal can; recommended to transfer to glass.

Sustainability and supply chain

• Cultivation often takes place in vocational areas with naturally fertile soils, which can reduce the need for synthetic inputs.

• Integrated and/or organic farming systems can lower environmental impact (pesticides, fertilisers).

• Precision irrigation reduces water consumption and limits nutrient leaching.

• By-products (skins, seeds, pulp residues) can be re-used for compost, extracts or tomato seed oil production.

• Metal (steel) and glass packaging have high recyclability rates, supporting circular-economy models.

• For PDO products, full traceability from field to can improves transparency and supports sustainable branding.

Main INCI functions (cosmetics)
Cosmetic ingredients derived from San Marzano tomatoes (or from tomato pulp/skins/seed oil of similar varieties) may perform the following functions:

• Antioxidant (due to lycopene and other carotenoids)

• Skin-conditioning agent (supporting softness and smoothness)

• Protective agent against environmental oxidative stress

• Soothing agent (supporting comfort of sensitive skin in suitable formulations)

• Refreshing agent in tonics, gels and after-sun products

Conclusion
San Marzano tomatoes are a flagship of Italian horticulture and tomato processing. Their distinctive morphology, intense flavour and favourable technological properties make them ideal for high-quality sauces, pizza toppings and traditional dishes. At the same time, their nutritional and phytochemical profile (especially lycopene and other antioxidants) offers interesting benefits for health-oriented products and cosmetic applications. When grown and processed within a controlled and certified supply chain, particularly under the PDO scheme, San Marzano tomatoes combine gastronomic excellence, nutritional value and strong identity linked to territory and tradition.

Mini-glossary

• SFA – Saturated fatty acids; should be limited because excessive intake is associated with increased cardiovascular risk.

• MUFA – Monounsaturated fatty acids; generally considered beneficial for blood lipid profile and heart health.

• PUFA – Polyunsaturated fatty acids; important for cell membranes and anti-inflammatory pathways.

• MRL – Maximum Residue Level; legal limit for pesticide residues in food.

• GMP – Good Manufacturing Practices; hygienic and organisational rules ensuring proper food production.

• HACCP – Hazard Analysis and Critical Control Points; preventive system for managing food-safety risks.

• BOD/COD – Biochemical Oxygen Demand / Chemical Oxygen Demand; indicators of the organic load of wastewater, relevant to environmental impact of processing plants.

• PDO – Protected Designation of Origin; EU quality scheme that protects products strongly linked to a specific geographical area and traditional know-how.

Studies

The tomato is rich in vitamins A and C and lycopene , the pigment that turns it red and is being studied for the prevention of many types of cancer, as it has antioxidant properties.

It is referred to by many studies as a prevention for prostate cancer (1).

Tomato varieties are many, including: Solanum arcanum, Solanum cheesmaniae, Solanum chilense, Solanum chmielewskii, Solanum corneliomuelleri, Solanum galapagense, Solanum habrochaites, Solanum huaylasense, Solanum neorickii, Solanum pennelli, Solanum perivianum, Solanum pimpinellifolium.

Carotenoid content in tomato

GMO tomatoes. Tomatoes have also been genetically modified, but European legislation requires that the term GMO be indicated on the label. There is no distinction in the USA. In terms of the components contained in the transgenic tomato Calcium and Magnesium are more abundant than the natural tomato.

Tomato studies

Health Benefits

Tomatoes have been associated with various health benefits, including the prevention of chronic diseases such as cancer, cardiovascular, and neurodegenerative diseases. The presence of antioxidants like lycopene plays a key role in these benefits.

Tomatoes have been associated with various health benefits, including the prevention of chronic diseases such as cancer, cardiovascular and neurodegenerative diseases. The presence of antioxidants such as lycopene plays a key role in these benefits.

Tomatoes are rich in vitamins A and C and lycopene, the pigment that produces the characteristic red coloring and is being studied for the prevention of many types of cancer, as it has antioxidant properties and plays a protective role for cardiovascular disease (1).

It is indicated by many studies as a prevention for prostate cancer (2), inhibits serum lipid peroxide production by improving the lipid profile (3)

References____________________________________________________________________

(1) Przybylska S, Tokarczyk G. Lycopene in the Prevention of Cardiovascular Diseases. Int J Mol Sci. 2022 Feb 10;23(4):1957. doi: 10.3390/ijms23041957. PMID: 35216071; PMCID: PMC8880080.

Abstract. Cardiovascular diseases (CVDs) are the leading cause of human mortality worldwide. Oxidative stress and inflammation are pathophysiological processes involved in the development of CVD. That is why bioactive food ingredients, including lycopene, are so important in their prevention, which seems to be a compound increasingly promoted in the diet of people with cardiovascular problems. Lycopene present in tomatoes and tomato products is responsible not only for their red color but also for health-promoting properties. It is characterized by a high antioxidant potential, the highest among carotenoid pigments. Mainly for this reason, epidemiological studies show a number of favorable properties between the consumption of lycopene in the diet and a reduced risk of cardiovascular disease. While there is also some controversy in research into its protective effects on the cardiovascular system, growing evidence supports its beneficial role for the heart, endothelium, blood vessels, and health. The mechanisms of action of lycopene are now being discovered and may explain some of the contradictions observed in the literature. This review aims to present the current knowledge in recent years on the preventive role of lycopene cardiovascular disorders.

(2) Salem S, Salahi M, Mohseni M, Ahmadi H, Mehrsai A, Jahani Y, Pourmand G. Major dietary factors and prostate cancer risk: a prospective multicenter case-control study. Nutr Cancer. 2011;63(1):21-7. doi: 10.1080/01635581.2010.516875.

Abstract. The association between diet and prostate cancer (PC) risk, although suggestive, still remains largely elusive particularly in the Asian population. This study sought to further evaluate the possible effects of different dietary factors on risk of PC in Iran. Using data from a prospective hospital-based multicenter case-control study, dietary intakes of red meat, fat, garlic, and tomato/tomato products, as well as thorough demographic and medical characteristics, were determined in 194 cases with the newly diagnosed, clinicopathologically confirmed PC and 317 controls, without any malignant disease, admitted to the same network of hospitals. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were obtained after adjustment for major potential confounders, including age, body mass index, smoking, alcohol, education, occupation, family history of PC, and total dietary calories. Comparing the highest with the lowest tertile, a significant trend of increasing risk with more frequent consumption was found for dietary fat (OR: 1.79, 95% CI: 1.71-4.51), whereas inverse association was observed for tomato/tomato products (OR: 0.33, 95% CI: 0.16-0.65). A nonsignificant increase in PC risk was revealed for dietary red meat (OR: 1.69, 95% CI: 0.93-3.06). For garlic consumption, a borderline reduction in risk was observed (OR: 0.58, 95% CI: 0.32-1.01; P = 0.05). In conclusion, our study supports the hypothesis that total fat may increase PC risk and tomatoes/tomato products and garlic may protect patients against PC.

(3) Effect of 12-Week Daily Intake of the High-Lycopene Tomato (Solanum Lycopersicum), A Variety Named "PR-7", on Lipid Metabolism: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study.  Nishimura M, Tominaga N, Ishikawa-Takano Y, Maeda-Yamamoto M, Nishihira J.  Nutrients. 2019 May 25;11(5). pii: E1177. doi: 10.3390/nu11051177.

Abstract. Tomato (Solanum lycopersicum) is a rich source of lycopene, a carotenoid that confers various positive biological effects such as improved lipid metabolism. Here, we conducted a randomized, double-blind, placebo-controlled, parallel-group comparative study to investigate the effects of regular and continuous intake of a new high-lycopene tomato, a variety named PR-7, for 12 weeks, based on 74 healthy Japanese subjects with low-density lipoprotein cholesterol (LDL-C) levels ≥120 to <160 mg/dL. The subjects were randomly assigned to either the high-lycopene tomato or placebo (lycopene-free tomato) group. Each subject in the high-lycopene group ingested 50 g of semidried PR-7 (lycopene, 22.0-27.8 mg/day) each day for 12 weeks, while subjects in the placebo group ingested placebo semidried tomato. Medical interviews were conducted, vital signs were monitored, body composition was determined, and blood and saliva samples were taken at weeks 0 (baseline), 4, 8, and 12. The primary outcome assessed was LDL-C. The intake of high-lycopene tomato increased lycopene levels in this group compared to levels in the placebo group (p < 0.001). In addition, high-lycopene tomato intake improved LDL-C (p = 0.027). The intake of high-lycopene tomato, PR-7, reduced LDL-C and was confirmed to be safe.

(4) Salehi B, Sharifi-Rad R, Sharopov F, Namiesnik J, Roointan A, Kamle M, Kumar P, Martins N, Sharifi-Rad J. Beneficial effects and potential risks of tomato consumption for human health: An overview. Nutrition. 2019 Jun;62:201-208. doi: 10.1016/j.nut.2019.01.012. Epub 2019 Jan 25. PMID: 30925445.

Przybylska S, Tokarczyk G. Lycopene in the Prevention of Cardiovascular Diseases. Int J Mol Sci. 2022 Feb 10;23(4):1957. doi: 10.3390/ijms23041957. 

Abstract. Cardiovascular diseases (CVDs) are the leading cause of human mortality worldwide. Oxidative stress and inflammation are pathophysiological processes involved in the development of CVD. That is why bioactive food ingredients, including lycopene, are so important in their prevention, which seems to be a compound increasingly promoted in the diet of people with cardiovascular problems. Lycopene present in tomatoes and tomato products is responsible not only for their red color but also for health-promoting properties. It is characterized by a high antioxidant potential, the highest among carotenoid pigments. Mainly for this reason, epidemiological studies show a number of favorable properties between the consumption of lycopene in the diet and a reduced risk of cardiovascular disease. While there is also some controversy in research into its protective effects on the cardiovascular system, growing evidence supports its beneficial role for the heart, endothelium, blood vessels, and health. The mechanisms of action of lycopene are now being discovered and may explain some of the contradictions observed in the literature. This review aims to present the current knowledge in recent years on the preventive role of lycopene cardiovascular disorders.