Granulated onion (Allium cepa L.)
Description
• Dehydrated product made from sound, mature onions that are peeled, sliced, dried, then granulated to a controlled mesh size.
• Sweet–sulfurous profile with clean vegetal notes; intensity and cleanliness depend on cultivar, process, and protection from humidity/oxygen.
• Physical form: free-flowing ivory–light yellow granules; may contain permitted anti-caking agents (e.g., silicon dioxide).
Caloric value (per 100 g)
• ~330–360 kcal; carbohydrate ~70–80 g (sugars and polysaccharides), fiber ~7–12 g, protein ~8–12 g, fat ~0.5–1.5 g; naturally low sodium.
• Culinary use levels are small, so per-portion energy is modest.
Key constituents
• Sugars (fructose, glucose, sucrose) and FOS (fructo-oligosaccharides).
• Sulfur precursors/volatiles: derivatives of S-alk(en)yl-L-cysteine sulfoxides; typical allyl/propyl di- and tri-sulfides.
• Organic acids: malic, citric; pyruvic acid used as a pungency marker.
• Minerals: potassium predominant; traces of calcium and magnesium.
• Typical specs: low moisture, target aw < 0.60; aqueous suspension pH ~5.0–6.0.
Production process
• Selection and trimming of bulbs → peeling, washing, slicing/lamination.
• Drying (hot air or vacuum/tunnel) to target moisture → cooling and deaeration.
• Granulation and sieving to the specified mesh.
• Sanitization (steam or equivalent) → barrier packaging under GMP/HACCP.
Sensory and technological properties
• Aroma: ready, clean, naturally sweet; sulfur notes develop further after hydration and during cooking.
• Functionality: excellent dispersibility and surface adhesion for dry rubs; contributes umami and Maillard browning.
• Hygroscopic: prone to caking without moisture control or anti-caking aid.
Food uses
• Seasoning blends, dry rubs for meat/fish/vegetables; sauces, marinades, soups, savory snacks, bakery items.
• Typical inclusion: 0.1–1.0% (optimize via pilot trials).
• Indicative equivalence: 1 level tsp granulated onion ≈ 1–2 Tbsp finely chopped fresh onion (varies by potency/supplier).
Nutrition and health
• Source of fiber (including FOS) and organosulfur compounds; fat negligible.
• FODMAP relevance: fructans can trigger GI symptoms in sensitive individuals—dose accordingly.
• Reactive thiosulfinates decrease with prolonged heating.
Quality and specifications (typical topics)
• Particle size (mesh), moisture (often ≤6–7%), aw, microbiology (TVC, yeasts/molds) and absence of pathogens.
• Volatile profile by GC–MS; pyruvic acid and sulfur pattern; HPLC markers when specified.
• Heavy metals/pesticides within limits; sensory: uniform color, no burnt/oxidized notes; foreign-matter free.
Storage and shelf-life
• Store cool, dry, tightly sealed, away from light and odors; prefer moisture-barrier packs.
• After opening: reclose immediately (zip/valved pouches; desiccant sachets as needed).
• Typical shelf-life 12–24 months if aw and packaging remain in spec; apply FIFO.
Allergens and safety
• Onion is not an EU major allergen, though individual sensitivities occur.
• Dried spices can carry Salmonella/spores → use sanitized lots and apply HACCP.
• Declare anti-caking agents and processing aids per regulations.
INCI functions (cosmetics)
• Typical entries: Allium Cepa Bulb Powder/Extract.
• Roles: masking, mild antioxidant, skin conditioning; manage the characteristic odor in formulas.
Troubleshooting
• Caking/clumping: moisture ingress → improve barrier, add permitted anti-caking agent, include desiccant sachets.
• Weak aroma: aged/oxidized lot → rotate (FIFO), upgrade barrier, minimize O₂ exposure.
• Bitter/burnt notes: over-toasting → reduce time/temperature or add later in process.
• Dark specks: overheating/oxidation → adjust heat curve and raw-material quality.
Sustainability and supply chain
• Upcycling of skins/trim into phenolic extracts or compost.
• Effluent management toward BOD/COD targets; drying energy efficiency; recyclable packaging.
• Full traceability and hygiene across the chain under GMP/HACCP.
Conclusion
Granulated onion combines convenience, stability, and immediate flavor. Clear specs (mesh, aw, aroma markers) and robust protection from humidity and oxygen deliver consistent quality and performance across applications.
Mini-glossary
• FOS — Fructo-oligosaccharides: fermentable carbohydrates (a FODMAP) that may affect sensitive individuals.
• aw — Water activity: “free” water available to microbes; lower aw improves stability.
• GC–MS — Gas chromatography–mass spectrometry: analytical profiling of volatiles.
• HPLC — High-performance liquid chromatography: quantifies markers (e.g., pyruvic acid, sulfur compounds).
• GMP — Good Manufacturing Practice: hygiene and process-consistency standards.
• HACCP — Hazard Analysis and Critical Control Points: preventive safety system with defined CCP.
• CCP — Critical Control Point: a step where control prevents/reduces a specific hazard.
• FIFO — First In, First Out: stock rotation prioritizing older lots first.
• BOD/COD — Biochemical/Chemical Oxygen Demand: indicators of wastewater organic load and environmental impact.
• CFU — Colony Forming Units: measure of viable microorganisms in microbiological testing.
Studies
Onions have antibacterial properties and can help reduce the risk of certain chronic diseases. Quercetin, found in onions, has been linked to preventing age-related diseases such as diabetes, cancer, and neurodegenerative diseases.
Animal studies have shown the effectiveness of onion as an anticoagulant.
Human studies have found the usefulness of onion combined with other vegetables to prevent cardiovascular problems.
As an anti-inflammatory, a component of the onion, Onionin A found in the bulb, has been shown to perform an action to counteract inflammatory blood activity (1).
There would also appear to be an action to improve the balance of blood sugar.
It is recommended, along with garlic, shallots and chives to prevent prostate cancer (2).
The best known red onions in Italy are the red head of Tropea and Certaldo.
Red onion studies
References________________________________________________________________________
(1) Fujiwara Y, Horlad H, Shiraishi D, Tsuboki J, Kudo R, Ikeda T, Nohara T, Takeya M, Komohara Y. O
(1) Fujiwara Y, Horlad H, Shiraishi D, Tsuboki J, Kudo R, Ikeda T, Nohara T, Takeya M, Komohara Y. Onionin A, a sulfur-containing compound isolated from onions, impairs tumor development and lung metastasis by inhibiting the protumoral and immunosuppressive functions of myeloid cells. Mol Nutr Food Res. 2016 Nov;60(11):2467-2480. doi: 10.1002/mnfr.201500995.
(2) Colli JL, Amling CL. Chemoprevention of prostate cancer: what can be recommended to patients? Curr Urol Rep. 2009 May;10(3):165-71. Review.
Abstract. Prostate cancer is third to lung and colon cancer as the cause of cancer-related deaths in American men. It is estimated that there will have been more than 28,000 deaths and 186,000 new cases in 2008 that will impose a significant burden on national health care costs. Chemoprevention aims to reduce both incidence and mortality through the use of agents to prevent, reverse, or delay the carcinogenic process. This study provides clinicians with information on some chemoprevention agents that have been considered to reduce prostate cancer risks, including 5-alpha-reductase inhibitors; statins (a class of compounds used to reduce cholesterol); NSAIDs; selenium; vitamins E and D; lycopene; allium vegetables (garlic, scallions, onions, chives, and leeks); soy/isoflavones; and green tea polyphenols. The evidence to support prostate cancer risk reduction benefits for each chemoprevention agent based on a review of the literature is provided.
Tsuboki J, Fujiwara Y, Horlad H, Shiraishi D, Nohara T, Tayama S, Motohara T, Saito Y, Ikeda T, Takaishi K, Tashiro H, Yonemoto Y, Katabuchi H, Takeya M, Komohara Y. Onionin A inhibits ovarian cancer progression by suppressing cancer cell proliferation and the protumour function of macrophages. Sci Rep. 2016 Jul 12;6:29588. doi: 10.1038/srep29588.
Abstract. It is well known that tumour-associated macrophages (TAMs) play an important role in tumour development by modulating the tumour microenvironment, and targeting of protumour activation or the M2 polarization of TAMs is expected to be an effective therapy for cancer patients. We previously demonstrated that onionin A (ONA), a natural low molecular weight compound isolated from onions, has an inhibitory effect on M2 macrophage polarization. In the present study, we investigated whether ONA had a therapeutic anti-ovarian cancer effect using in vitro and in vivo studies. We found that ONA reduced the extent of ovarian cancer cell proliferation induced by co-culture with human macrophages. In addition, we also found that ONA directly suppressed cancer cell proliferation. A combinatorial effect with ONA and anti-cancer drugs was also observed. The activation of signal transducer and activator of transcription 3 (STAT3), which is involved in cell proliferation and chemo-resistance, was significantly abrogated by ONA in ovarian cancer cells. Furthermore, the administration of ONA suppressed cancer progression and prolonged the survival time in a murine ovarian cancer model under single and combined treatment conditions. Thus, ONA is considered useful for the additional treatment of patients with ovarian cancer owing to its suppression of the protumour activation of TAMs and direct cytotoxicity against cancer cells.
Li Q, Wang Y, Mai Y, Li H, Wang Z, Xu J, He X. Health Benefits of the Flavonoids from Onion: Constituents and Their Pronounced Antioxidant and Anti-neuroinflammatory Capacities. J Agric Food Chem. 2020 Jan 22;68(3):799-807. doi: 10.1021/acs.jafc.9b07418.
Abstract. Onion is the most widely cultivated vegetable around the world. In this study, the isolation, concentration, quantification, and bioactivity evaluation of the phenolics in onion peels were investigated. Thirty-four phenolics, including 17 flavonoids and 17 nonflavonoid phenolics, were purified and identified. Among them, there were 2 new unusual epoxyflavanones and a new phenolic constituent, as well as 13 unreported constituents from the genus Allium. The total flavonoids were concentrated, and finally obtained 90.25% of flavonoid content extract. Fifteen main flavonoids were quantified using an ultra-performance liquid chromatography-photodiode array (UPLC-PDA), and quercetin (36.94%) and quercetin 4'-O-β-d-glucopyranoside (15.81%) were the richest contents of flavonoids. The antioxidant and anti-neuroinflammatory capacities were evaluated, and the bioactive results indicated that the flavonoids in onion exhibited pronounced activities. The study suggested that the flavonoids in onion peels could be used in functional food.
Yoo Y, Kim S, Lee W, Kim J, Son B, Lee KJ, Shin H. The prebiotic potential of dietary onion extracts: shaping gut microbial structures and promoting beneficial metabolites. mSystems. 2025 Jan 21;10(1):e0118924. doi: 10.1128/msystems.01189-24.
Abstract. Onions are well-known vegetables that offer various health benefits. This study explores the impact of onion extracts on gut microbiome using an in vitro fecal incubation model and metabolome analysis. Fecal samples were collected from 19 healthy donors and incubated in the presence or absence of onion extracts for 24 h. To reduce inter-individual variability in the gut microbiome, we employed enterotyping based on baseline fecal microbiota: 14 subjects with a Bacteroides-dominant type (enterotype B) and 5 subjects with Prevotella-dominant type (enterotype P). Alpha diversity was significantly reduced in the onion-treated group compared to the non-treated control group in both Bacteroides- and Prevotella-dominant types. However, significant structural differences in bacterial communities were observed based on weighted UniFrac distance. Notably, short-chain fatty acid (SCFA)-producing bacteria, such as Bifidobacterium_388775, Feacalibacterium, and Fusicatenibacter, were overrepresented in response to onion extracts in enterotype B. Furthermore, genes related to butyrate production were significantly overrepresented in the onion-treated group within enterotype B. Consistent with the enriched taxa and the predicted metabolic pathways, SCFAs and their related metabolites were significantly enriched in the onion-treated group. Additionally, tryptophan metabolism-derived metabolites, including indolelactate (ILA) and indolepropionate (IPA), were elevated by 4- and 32-fold, respectively, in the onion-treated group compared to the control group. In vitro growth assays showed an increase in lactobacilli strains in the presence of onion extracts. These results provide evidence that onion extracts could serve as promising prebiotics by altering gut microbial structure and promoting the production of beneficiary metabolites, including SCFAs and indole derivatives, and enhancing the growth of probiotics.IMPORTANCEThis study is significant as it provides compelling evidence that onion extracts have the potential to serve as effective prebiotics. Utilizing an in vitro fecal incubation model and enterotyping to reduce inter-individual variability, the research demonstrates how onion extracts can alter gut microbial structure and promote the production of beneficial metabolites, including SCFAs and indole derivatives like ILA and IPA. Additionally, onion extract treatment enhances the growth of beneficial probiotics. The findings underscore the potential of onion extracts to improve gut health by enriching specific beneficial bacteria and metabolic pathways, thereby supporting the development of functional foods aimed at improving gut microbiota composition and metabolic health.
Dorrigiv M, Zareiyan A, Hosseinzadeh H. Onion (Allium cepa) and its Main Constituents as Antidotes or Protective Agents against Natural or Chemical Toxicities: A Comprehensive Review. Iran J Pharm Res. 2021 Winter;20(1):3-26. doi: 10.22037/ijpr.2020.112773.13940.
Abstract. Onion (Allium cepa) is a member of the family Amaryllidaceae and one of the most widely cultivated species of the genus Allium. Onion has plentiful chemical compounds such as allicin, quercetin, fisetin, other sulphurous compounds: diallyl disulphide and diallyl trisulphide. Onion and its main components in specific doses have shown a lot of benefits including free-radical scavenging and antioxidant properties, anticholesterolemic, anti-heavy metals toxicity, antihyperuricemia, antimicrobial, anti-gastric ulcer, and anticancer. This study summarizes numerous in-vitro and animal studies on the protective effects of onion against natural and chemical toxicities. Onion and its main components can ameliorate the toxicity of chemical agents in kidney, liver, brain, blood, heart, reproductive system, embryo, pancreas through reducing lipid peroxidation, antioxidant effect, radical-scavenging, anti-inflammatory, chelating agent, cytoprotective activities, increasing protein synthesis in damaged tissues, suppressing apoptosis, as well as modulation of PKC-
Granulated Onion 
