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 | "Descrizione" by Al222 (24891 pt) | 2026-Jan-08 12:05 |
Torula yeast (Cyberlindnera jadinii / Candida utilis) – identity, composition, cosmetic and food uses, and safety notes
Torula yeast biomass / inactivated yeast – Cyberlindnera jadinii (syn. Candida utilis)
Synonyms: Torula, Torula yeast, Cyberlindnera jadinii, Candida utilis (historical name), inactivated yeast, torula yeast powder
INCI / functions: most cosmetic uses are implemented via related INCI entries such as Yeast Extract, Hydrolyzed Yeast Extract, or Yeast Ferment Extract, with functions primarily skin conditioning (and, depending on the INCI, also skin protecting)
Definition
Torula yeast is an inactive yeast biomass obtained from the yeast species Cyberlindnera jadinii (historically known in industry as Candida utilis). From a compositional standpoint, torula yeast is a complex biological matrix that typically contains proteins and peptides, free amino acids, carbohydrates (including cell-wall polysaccharides such as β-glucans and mannans, grade-dependent), B-group vitamins (content depends on process and substrate), minerals (ash), and minor fractions such as nucleotides and lipids (usually low).
In practical use, the “torula yeast” name is common in food and feed supply chains (savory/umami contribution, protein biomass), while in cosmetics it is more often present as yeast-derived extracts/ferments (INCI-defined) rather than as the whole biomass.
Torula yeast is not just any yeast. It's a byproduct of the paper industry, where it's grown on wood sugars, specifically from the spent sulfite liquor process. However, for culinary and nutritional applications, it's typically cultured on molasses, which provides a sustainable and efficient growth medium. This yeast thrives, consuming the sugars and minerals present, and in the process, it multiplies and produces a biomass rich in proteins, vitamins, and minerals.
Nutritional Depth
- Protein Quality: High protein content, up to 50% of its dry weight, making it a good source of plant-based protein. Torula yeast's protein is high in quality, containing all nine essential amino acids, making it a complete protein source. This is particularly important for those following plant-based diets who might find it challenging to obtain complete proteins.
- Vitamin B Complex: Rich in B-complex vitamins, especially B1, B2, B3, and B6, which are essential for energy metabolism. The richness in B vitamins makes Torula yeast an exceptional supplement, especially vitamin B12. Often, B12 is cited as a nutrient of concern for those not consuming animal products, as it's predominantly found in meat and dairy. Torula yeast offers a bioavailable form of B12, along with thiamine (B1), riboflavin (B2), niacin (B3), and pyridoxine (B6), supporting energy metabolism, neurological function, and red blood cell formation.
- Mineral Content: Contains minerals such as iron, magnesium, and zinc. It's a source of essential minerals, including selenium, a powerful antioxidant that supports immune function and thyroid health; zinc, crucial for immune response, wound healing, and DNA synthesis; and iron, necessary for transporting oxygen in the blood.
- Fiber: Contains a good amount of fiber.
Food: savory ingredient and functional yeast biomass; also used for texture and flavor positioning depending on grade.
Cosmetics: typically via yeast extracts/ferments as skin conditioning (and sometimes skin protecting) ingredients.
Medicine: mainly research relevance (microbiology/biotech), not a standard medical ingredient.
Pharmaceutical: possible excipient/research relevance depending on grade and dossier.
Industrial use: biotechnology host and technical yeast biomass for multiple industrial applications; also used in traps/attractant applications in agriculture (sector-dependent).
Calories (energy value)
| Metric | Value |
|---|---|
| Energy value (100 g) | ~370 kcal (indicative for dried torula yeast powder) |
| Technical note | Cosmetic use is usually at low inclusion (when present as extracts/ferments), so energy impact on finished products is negligible |
Identification data and specifications
| Category | Value |
|---|---|
| Biological identity | Cyberlindnera jadinii (syn. Candida utilis) |
| Ingredient type (typical) | inactive dried yeast biomass (powder) or yeast-derived extract/ferment (cosmetic ingredient) |
| CAS / EC numbers | Not typically applicable to whole yeast biomass as a single “chemical substance” (verify supplier SDS/CoA for the exact commercial grade) |
| Cosmetic-relevant INCI examples | Primary declared functions (INCI) |
|---|---|
| Yeast Extract | skin conditioning, skin protecting |
| Hydrolyzed Yeast Extract | skin conditioning |
| Yeast Ferment Extract | skin conditioning |
Key constituents
| Constituent group | Main components | What they influence |
|---|---|---|
| Proteins / peptides | yeast proteins, peptide fractions (grade-dependent) | functional positioning (food protein biomass), sensory/feel (extracts) |
| Amino acids | free amino acids and small peptides | savory profile (food) and conditioning concept (cosmetics) |
| Carbohydrates / cell wall | β-glucans, mannans (grade-dependent) | viscosity/texture interactions; potential soothing/conditioning positioning (needs product evidence) |
| Micronutrients | B-group vitamins and minerals (variable) | nutritional positioning (food/feed), QC markers (ash, specific vitamins) |
| Minor fractions | nucleotides, low lipids | flavor contribution (food) and stability/odor considerations |
Physicochemical properties (practical)
| Property | Typical observation | Notes |
|---|---|---|
| Physical form | powder (dried biomass) | particle size and flow vary by drying method/grade |
| Solubility | often insoluble as whole biomass; partial dispersibility | yeast extracts are more soluble than whole biomass |
| Odor | yeasty/savory (grade-dependent) | critical for fragranced cosmetics: odor masking may be needed |
| Oxidation sensitivity | generally manageable | monitor odor drift; storage and packaging matter |
Functional role in formulation
| Function | Role in the finished product | Operational notes |
|---|---|---|
| Skin conditioning (extract/ferment) | supports skin feel/conditioning positioning | requires compatibility testing and finished-product substantiation |
| Skin protecting (where declared) | supports barrier/protection concept | align with claim strategy and evidence |
| Food savory ingredient (biomass) | contributes to umami/savory profile and can support texture | depends strongly on processing, dosage, and matrix |
Formulation compatibility
| System | Compatibility | Controls to run |
|---|---|---|
| O/W emulsions (cosmetics) | to be assessed | odor, color, stability under thermal cycling, preservative compatibility |
| Surfactant systems (rinse-off) | often compatible (extract/ferment) | check foam/clarity and odor evolution |
| Clear gels | sensitive | haze risk; optimize solubilization and polymer choice |
| Preservatives | critical | yeast-derived materials can increase bioburden risk; validate with challenge testing |
Use guidelines (indicative)
| Use context | Typical range | Technical note |
|---|---|---|
| Cosmetics (yeast extract/ferment) | 0.1–5.0% | follow supplier dossier; start low for odor/color control |
| Food ingredient (torula yeast biomass) | 0.2–10% | range depends on food category and objective |
| Feed / pet food | variable | define by nutritional target, palatability, and regulatory framework |
Typical applications
Food: soups, sauces, seasonings, processed savory products; also as a protein biomass ingredient.
Cosmetics: leave-on and rinse-off products using yeast extracts/ferments for skin conditioning positioning.
Industrial/biotech: host organism and biomass applications in industrial fermentation settings (grade- and process-dependent).
Quality, grades and specifications
| QC topic | What to specify and control |
|---|---|
| Identity | organism identity and traceability to C. jadinii / C. utilis lineage |
| Composition | protein (typical dry biomass can be around ~50% on dry weight), ash, moisture, and marker profile (supplier-defined) |
| Microbiology | total counts and pathogen absence per intended use (food/cosmetic) |
| Sensory | odor and color stability (especially for cosmetics) |
| Documentation | CoA and SDS aligned to the purchased grade and intended sector |
Safety, regulatory and environment
| Topic | Operational guidance |
|---|---|
| Safety profile | generally manageable; treat as a biologically derived material (dust control for powders; avoid inhalation) |
| Sensitization/irritation | possible individual sensitivity; confirm via finished-product safety assessment |
| EU food status | torula yeast biomass has been considered not novel for use as a food ingredient in the EU (food-only framing) |
| EU cosmetics | when used via INCI yeast extracts/ferments, apply standard EU cosmetic safety assessment and GMP |
| Environment | manage effluents and residues per local rules; avoid uncontrolled release of organic load |
Formulation troubleshooting
| Issue | Likely cause | Corrective actions |
|---|---|---|
| Haze/particles in gels | insoluble biomass or incomplete solubilization | switch to a more soluble yeast extract, add solubilization step, adjust polymer system |
| Odor impact | intrinsic yeasty/savory odor | reduce dose, use deodorized grades, incorporate odor-masking strategy (where acceptable) |
| Microbiological instability | higher bioburden or preservative incompatibility | tighten raw-material specs, optimize preservatives, run challenge tests and stability |
| Batch-to-batch variability | natural variability in biomass/extract composition | define acceptance criteria (protein/ash/odor markers), qualify suppliers |
Conclusion
Torula yeast is a well-established inactive yeast biomass associated with Cyberlindnera jadinii (syn. Candida utilis), used widely in food and feed and, in cosmetics, more commonly via yeast-derived extracts/ferments with skin conditioning (and sometimes skin protecting) functions. The main technical success factors are grade selection, odor/color control, strong microbiological specification, and finished-product validation for stability and performance.
Mini-glossary
| Term | Meaning | Note |
|---|---|---|
| β-glucans | yeast cell-wall polysaccharides | grade-dependent content; may affect texture and conditioning positioning |
| CoA | Certificate of Analysis | defines lot specifications (assay, microbiology, moisture, etc.) |
| SDS | Safety Data Sheet | authoritative for handling, hazards, and regulatory identifiers |
| Inactive yeast | yeast biomass rendered non-viable | commonly used for food ingredients and stable powders |
References__________________________________________________________________________
Timlin CL, Dickerson SM, Fowler JW, Mccracken FB, Skaggs PM, Ekmay R, Coon CN. The effects of torula yeast as a protein source on apparent total tract digestibility, inflammatory markers, and fecal microbiota dysbiosis index in Labrador Retrievers with chronically poor stool quality. J Anim Sci. 2024 Jan 3;102:skae013. doi: 10.1093/jas/skae013.
Abstract. This study examined the effects of varying protein sources on apparent total tract digestibility, inflammatory markers, and fecal microbiota in Labrador Retrievers with historically poor stool quality. Thirty dogs (15 male, 15 female; aged 0.93 to 11.7 yr) with stool quality scores ≤2.5 on a 5-point scale (1 representing liquid stool and 5 representing firm stool) were randomly assigned to 1 of 3 nutritionally complete diets with differing protein sources and similar macronutrient profiles: 1) chicken meal (n = 10); 2) 10% brewer's yeast (n = 10); or 3) 10% torula yeast (n = 10). Another 10 dogs (five male, five female) with normal stool quality (scores ranging from 3 to 4) received diet 1 and served as negative control (NC). All dogs were fed diet 1 for 7 days, then provided their assigned treatment diets from days 7 to 37. Daily stool scores and weekly body weights were recorded. On days 7, 21, and 36, blood serum was analyzed for c-reactive protein (CRP), and feces for calgranulin C (S100A12), α1-proteinase inhibitor (α1-PI), calprotectin, and microbiota dysbiosis index. Apparent total tract digestibility was assessed using the indicator method with 2 g titanium dioxide administered via oral capsules. Stool scores were greater in NC (P < 0.01) as designed but not affected by treatment × time interaction (P = 0.64). Body weight was greater (P = 0.01) and CRP lower (P < 0.01) in NC dogs. Dry matter and nitrogen-free extract digestibility did not differ among groups (P ≥ 0.14). Negative controls had greater fat digestibility compared to BY (94.64 ± 1.33% vs. 91.65 ± 1.25%; P = 0.02). The overall effect of treatment was significant for protein digestibility (P = 0.03), but there were no differences in individual post hoc comparisons (P ≥ 0.07). Treatment did not affect S100A12 or α1-PI (P ≥ 0.44). Calprotectin decreased at a greater rate over time in TY (P < 0.01). The dysbiosis index score for BY and TY fluctuated less over time (P = 0.01). Blautia (P = 0.03) and Clostridium hiranonis (P = 0.05) abundances were reduced in BY and TY. Dogs with chronically poor stool quality experienced reduced body weights and increased serum CRP, but TY numerically increased protein digestibility, altered the microbiome, and reduced fecal calprotectin. Torula yeast is a suitable alternative protein source in extruded canine diets, but further research is needed to understand the long-term potential for improving the plane of nutrition and modulating gut health.
Verstrepen L, Calatayud-Arroyo M, Duysburgh C, De Medts J, Ekmay RD, Marzorati M. Amino Acid Digestibility of Different Formulations of Torula Yeast in an In Vitro Porcine Gastrointestinal Digestion Model and Their Protective Effects on Barrier Function and Inflammation in a Caco-2/THP1Co-Culture Model. Animals (Basel). 2023 Sep 5;13(18):2812. doi: 10.3390/ani13182812.
Abstract. Single-cell protein from torula yeast (Cyberlindnera jadinii) grown on lignocellulosic biomass has been proven to be an excellent alternative protein source for animal feed. This study aimed to evaluate the amino acid (AA) digestibility by estimating intestinal absorption from three yeast-based ingredients, produced by cultivating C. jadinii on hydrolysate, using either mixed woody species (drum- (WDI) or spray-dried (WSI)) or corn dextrose (drum-dried (DDI)) as the carbon source. Further, the protective effect of intestinal digests on activated THP1-Blue™-induced epithelial damage and cytokine profile was evaluated. Total protein content from these three ingredients ranged from 34 to 45%, while the AA dialysis showed an estimated bioaccessibility between 41 and 58%, indicating good digestibility of all test products. A protective effect against epithelial-induced damage was observed for two of the three tested products. Torula yeast cultivated on wood and drum-dried (WDI) and torula yeast cultivated on wood and spray-dried (WSI) significantly increased transepithelial electrical resistance (TEER) values (111-147%, p < 0.05), recovering the epithelial barrier from the inflammation-induced damage in a dose-dependent manner. Further, WSI digests significantly reduced IL8 (250.8 ± 28.1 ng/mL), IL6 (237.9 ± 1.8 pg/mL) and TNF (2797.9 ± 216.3 pg/mL) compared to the blank control (IL8 = 485.7 ± 74.4 ng/mL, IL6 = 478.7 ± 58.9 pg/mL; TNF = 4273.5 ± 20.9 pg/mL) (p < 0.05). These results align with previous in vivo studies, supporting torula yeast-based ingredients as a high-quality protein source for pigs, protecting the intestinal barrier from inflammatory damage, and reducing the pro-inflammatory response. We provided novel insights into the mechanisms behind the health improvement of pigs fed on torula yeast-based ingredients, with potential applications for designing nutritional interventions to recover intestinal homeostasis during critical production periods, such as weaning.
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