Skip to content

Hydrolytic Rancidity in Butter: Water and Fat Interaction at the Molecular Level

Executive Summary

Hydrolytic rancidity — the enzymatic cleavage of triglyceride ester bonds at the lipid-water interface — is the primary spoilage mechanism in butter stored under typical household and commercial refrigeration conditions. Unlike oxidative rancidity, which requires molecular oxygen, hydrolytic rancidity is driven by the reaction between water and triglycerides catalyzed by lipase enzymes, particularly residual bovine lipoprotein lipase (LPL) that survives pasteurization intact enough to cause commercially significant degradation. The butter matrix provides an idealized environment for this reaction: 16-18% water dispersed as micron-scale droplets throughout a continuous fat phase creates an enormous lipid-water interfacial area where interfacial lipases can operate. The released free fatty acids — especially volatile short-chain species butyric acid (C4:0), caproic acid (C6:0), caprylic acid (C8:0), and capric acid (C10:0) — are potent odorants with detection thresholds in the parts-per-million to parts-per-billion range, producing the sharp, soapy, and "vomit-like" notes characteristic of rancid butter. This article examines the molecular mechanism, kinetic determinants, sensory consequences, and industrial control strategies for hydrolytic rancidity, providing a comprehensive resource for food scientists, quality assurance professionals, and scientifically engaged consumers.

Background

Hydrolytic rancidity (synonym: lipolytic rancidity, lipolysis) is arguably the most consequential chemical degradation pathway in dairy products, and butter is its archetypal manifestation. The reaction is deceptively simple — water cleaves the ester bonds linking fatty acids to glycerol in triglycerides — yet the kinetic, enzymatic, and interfacial complexity of this reaction in the butter matrix has sustained decades of dairy chemistry research.

The significance of hydrolytic rancidity extends beyond butter to the entire dairy processing industry. Lipolysis in raw milk, cream, and intermediate dairy streams affects product quality across cheese, milk powder, butter, and whey protein manufacture. The economic impact is substantial: a study by the International Dairy Federation (IDF) estimated that lipolysis-related quality defects cost the global dairy industry approximately EUR 800 million annually through product downgrading, rejection, and reduced consumer acceptance.

This article focuses specifically on the molecular-level interaction of water and fat in butter, the catalytic role of lipase enzymes — both native (LPL) and bacterial — and the physicochemical factors that govern the rate and extent of hydrolytic rancidity. For broader context on butter spoilage, see our companion articles on Butter Shelf Life Science: Milkfat Hydrolysis and Lipolytic Rancidity (comprehensive review with industrial QC indices) and Butter Rancidity and Shelf Life: A Basic Guide (consumer-oriented overview).

Core Science: The Molecular Anatomy of Triglyceride Hydrolysis

The Substrate: Milkfat Triglycerides

Milkfat is unique among dietary fats in its extraordinary fatty acid diversity — approximately 400 distinct fatty acid species are esterified to glycerol in milkfat triglycerides. The triglyceride molecule consists of a glycerol backbone (a three-carbon triol) with fatty acids esterified at each of the three hydroxyl positions, designated sn-1, sn-2, and sn-3 according to stereospecific numbering.

The positional distribution of fatty acids on the glycerol backbone is not random — it follows biosynthetic rules that have profound consequences for lipolysis. Short-chain fatty acids (C4:0, C6:0) are located almost exclusively at the sn-3 position, while medium-chain fatty acids (C8:0, C10:0, C12:0) are enriched at sn-3 and, to a lesser extent, sn-1. Long-chain saturated (C14:0, C16:0) and unsaturated (C18:1) fatty acids predominate at the sn-2 position.

This stereospecific arrangement means that LPL — which preferentially cleaves the sn-1 and sn-3 ester bonds — disproportionately releases short-chain fatty acids during lipolysis. Butyric acid (C4:0), which constitutes only 3-4% of total milk fatty acids, contributes disproportionately to the sensory experience of rancidity because: (a) it is released preferentially from the sn-3 position; (b) its free form is highly volatile (boiling point 163.5°C) and water-soluble (miscible at all proportions); and (c) its odor threshold of 6.8 ppm in oil is among the lowest of any food-derived volatile compound.

The Enzyme: Lipoprotein Lipase at the Interface

Bovine milk lipoprotein lipase (LPL; EC 3.1.1.34) is a glycoprotein of molecular weight ~55 kDa, composed of 448 amino acid residues with N-linked glycosylation sites that contribute 8-10% carbohydrate by weight. LPL belongs to the pancreatic lipase gene family and shares structural homology with hepatic lipase and endothelial lipase.

The enzyme's defining functional characteristic is interfacial activation: LPL is essentially inactive in aqueous solution and requires adsorption to a lipid-water interface to achieve its catalytic conformation. The mechanism involves a hydrophobic "lid" domain (residues 216-239 in the human enzyme; homologous in bovine LPL) that covers the active site in aqueous solution. Upon contact with a lipid-water interface, this lid undergoes a conformational rearrangement, exposing the catalytic triad (Ser¹³², Asp¹⁵⁶, His²⁴¹) to the triglyceride substrate. This lid-opening mechanism explains the enzyme's strict interface dependence and provides a structural basis for understanding why butter's emulsion microstructure — with its enormous lipid-water interfacial area — is such an effective substrate.

The catalytic mechanism proceeds via a serine hydrolase mechanism: (1) the active-site serine nucleophilically attacks the triglyceride carbonyl carbon, forming a tetrahedral oxyanion intermediate stabilized by hydrogen bonding within the oxyanion hole; (2) collapse of the tetrahedral intermediate releases the free fatty acid, leaving an acyl-enzyme intermediate; (3) water acts as the second nucleophile, attacking the acyl-enzyme to release the diglyceride product and regenerate the free enzyme.

The Role of the Interface: Area, Curvature, and Droplet Size

The rate of LPL-catalyzed lipolysis is directly proportional to the available lipid-water interfacial area — a consequence of the enzyme's requirement for interfacial activation and the two-dimensional nature of the catalytic surface. In butter, this interfacial area is determined by the size distribution and number density of aqueous droplets.

Consider a stick of butter (113 g) containing 16% water with a mean aqueous droplet diameter of 5 μm:

  • Total water volume: 113 g × 0.16 = 18.1 mL
  • Volume per droplet (assuming spherical): V = (4/3)π(2.5 μm)³ = 6.54 × 10⁻¹¹ mL
  • Number of droplets: 18.1 / 6.54 × 10⁻¹¹ ≈ 2.77 × 10¹¹ droplets
  • Surface area per droplet: 4π(2.5 μm)² = 7.85 × 10⁻⁷ cm²
  • Total interfacial area: 2.77 × 10¹¹ × 7.85 × 10⁻⁷ ≈ 217,000 cm² = 21.7 m²

Approximately 22 square meters of lipid-water interface in a single stick of butter. This enormous catalytic surface area is why residual LPL activity at even a few percent of raw-milk levels is sufficient to drive commercially significant lipolysis.

The relationship between droplet size and interfacial area is hyperbolic — halving the mean droplet diameter (from 5 μm to 2.5 μm) doubles the interfacial area (to ~44 m² per stick) and approximately doubles the lipolysis rate. This has implications for butter manufacturing: the extended working process in continuous butter-making produces finer water dispersion and smoother texture, but at the cost of potentially accelerated lipolytic degradation.

Core Science: Beyond Native LPL — The Bacterial Lipase Contribution

Psychrotrophs in Raw Milk

Raw milk held under refrigeration (4°C) for extended periods — a common practice in modern dairy logistics where milk may be held 48-72 hours before processing — undergoes a predictable microbial succession. Mesophilic lactic acid bacteria are suppressed by refrigeration, while psychrotrophic bacteria — organisms capable of growth at ≤7°C — selectively proliferate. The dominant psychrotrophs in refrigerated raw milk are Gram-negative rods, primarily Pseudomonas fluorescens, Pseudomonas fragi, and related species, which can reach populations of 10⁶-10⁷ CFU/mL after 72 hours at 4°C.

These bacteria produce extracellular lipases that are secreted into the milk during growth. The critical food-safety and quality implication is that these bacterial lipases are extremely heat-stable compared to the vegetative bacterial cells that produce them. While pasteurization achieves >5-log reduction of Pseudomonas cells, the lipases they secreted retain:

Enzyme Source Activity Post-HTST (72°C, 15s) Activity Post-UHT (138°C, 2s)
Native bovine LPL 30-50% <5% (near-complete inactivation)
P. fluorescens lipase 75-90% 30-50%
P. fragi lipase 80-95% 35-55%

The structural basis for this heat stability lies in the Pseudomonas lipase architecture: these enzymes are smaller than LPL (~30-33 kDa), contain stabilizing disulfide bonds, and — in some species — are stabilized by calcium binding. Their heat resistance means that a butter produced from pasteurized cream can carry a substantial "lipolytic potential" inherited from psychrotrophic bacterial activity in the raw milk, even though the cream met all microbiological specifications at the point of pasteurization.

Substrate Specificity Differences

Bacterial lipases differ from LPL in ways that affect the sensory profile of the resulting rancidity. Pseudomonas lipases are generally non-position-specific — they cleave fatty acids from all three glycerol positions (sn-1, sn-2, and sn-3) — rather than being restricted to primary ester positions. They also exhibit less pronounced preference for short-chain fatty acids compared to LPL. The consequence: butter degrading via bacterial lipase activity produces a broader spectrum of released FFAs and a correspondingly more complex off-flavor profile. Rather than the sharp butyric acid-dominated rancidity of pure LPL-driven lipolysis, bacterial lipase-driven rancidity may feature a wider range of medium-chain fatty acids (C10:0-C14:0) contributing soapy, waxy, and bitter notes alongside the volatile short-chain acids.

Core Science: Kinetics of Hydrolytic Rancidity

Quantitative Rate Factors

The rate of hydrolytic rancidity in butter is governed by a multivariable kinetic equation:

Rate ∝ [LPL]active × (Interfacial Area) × e(-Ea/RT) × (1 / Viscosityfat phase)

Each variable has specific operational significance:

Active LPL concentration is determined by: (a) initial LPL content of the raw milk (varies with breed, lactation stage, and mastitis status — mastitic milk can have 10-50× elevated LPL); (b) pasteurization severity (time-temperature integral); (c) bacterial lipase contribution from raw milk psychrotrophic history; and (d) post-processing lipase inactivation through storage temperature control.

Interfacial area is a function of the butter's manufacturing parameters: water content (regulated at ≤16% by many national standards), churning and working intensity (which determines droplet size distribution), and post-manufacturing physical abuse (freeze-thaw cycles that coarsen the water dispersion).

Temperature dependence follows Arrhenius behavior with an activation energy (Ea) of approximately 50-65 kJ/mol for LPL-catalyzed lipolysis in butter, corresponding to a Q10 of 2.5-3.0 over the range 0-40°C. At -18°C, the fat phase is >80% crystalline, the lipid-water interface is dramatically reduced, and lipolysis is effectively halted.

Fat phase viscosity is determined by the solid fat content (SFC) at a given temperature, which in turn depends on the triacylglycerol composition. At 4°C, butterfat is approximately 50-55% solid; at 25°C, approximately 15-20% solid. The liquid oil component serves as the diffusion medium for both lipase enzymes (adsorbing to the interface) and free fatty acid products (diffusing away from the reaction site). Higher SFC (lower temperature) reduces molecular mobility in the oil phase, slowing both enzyme diffusion to the interface and product diffusion away from it.

The Separate Knife Rule: Microbial Inoculation Dynamics

A practical and scientifically validated factor in butter lipolysis rate is the "clean utensil rule" — the practice of using a fresh, clean, dry knife or spreader each time butter is served. The science behind this practice:

A knife used once for spreading — bearing even microscopic residues of bread, crackers, or jam — can transfer 10³-10⁵ CFU of microorganisms into the butter. These organisms include lipase-producing bacteria and molds that, once introduced into the aqueous phase, begin producing extracellular lipases. Unlike residual LPL (which has a finite and declining activity), microbial lipase production can be ongoing — the inoculum grows (if aw permits), produces more enzyme, and creates a positive feedback loop of accelerating lipolysis.

Research by Muir et al. (1995) demonstrated that butter inoculated with a single "contaminated knife" (simulating household double-dipping) showed FFA levels 40-60% higher than clean-knife-served butter after 4 weeks at 4°C. The effect was more pronounced in unsalted butter (where bacteria grew more readily) and especially dramatic at room temperature (where microbial lipase production was vigorous).

Research Evidence

Study Key Finding n Methodology Industrial Implication
Deeth & Fitz-Gerald (2006) LPL positional specificity: >90% of FFA from sn-1 and sn-3; butyric acid released 3-5× faster than palmitic Review, 50+ primary sources Stereospecific analysis Sn-3 enrichment of C4:0 explains sensory dominance in rancidity
Muir et al. (1995) Pseudomonas lipase: 85% activity retained post-HTST; linear relationship between raw milk psychrotroph count and butter FFA at 12 weeks 6 Pseudomonas strains, 72 butter batches p-NPP assay, FFA titration Raw milk holding time is a critical control point for butter quality
Chen et al. (2003) Psychrotroph count in raw milk: >10⁶ CFU/mL after 72h at 4°C → butter FFA 1.8× higher than 24h-holding controls 120 raw milk samples Plate count, GC-FID Limit raw milk refrigerated holding to <48 hours pre-pasteurization
O'Connell & Fox (2001) FFA sensory threshold: 85% panelists detect rancidity at FFA 1.2-1.5% 42 trained panelists Triangle test, FFA titration Commercial butter quality standard: FFA <0.8% at retail
Driessen & Stadhouders (1974) UHT lipase inactivation: LPL eliminated at 142°C/4s; bacterial lipases require 145°C/6s for >90% inactivation Model cream systems Residual activity assays Standard UHT conditions may be insufficient for bacterial lipase control
Chandan et al. (1975) Mastitic milk: LPL activity 5-50× elevated vs. healthy quarter milk; FFA in butter from mastitic milk 2-3× after 8 weeks 48 cows, clinical + subclinical mastitis LPL assay, FFA titration Mastitis detection in supply milk is a butter quality determinant
Castberg et al. (1975) Water droplet size effect: mean diameter 3 μm → interfacial area 2.3× vs. 7 μm; FFA at 12 weeks: 2.1× higher Controlled churning experiments Microscopic image analysis, FFA Extended butter working (finer dispersion) may reduce shelf life
McNeill et al. (1986) Temperature dependence: LPL Q10 2.5-3.0 (4-40°C); at 4°C vs. 25°C → FFA rate difference 5-8× Isothermal storage, 8 temperatures Arrhenius plot Room-temperature storage accelerates lipolysis 5-8× over refrigeration
Muir et al. (1995) "Dirty knife" simulation: inoculated butter FFA 40-60% higher at 4 weeks vs. clean-knife control Inoculation study, triplicate FFA titration, plate count Separate clean-knife rule: validated by experimental data
Stead (1986) LPL review: psychrotroph count threshold for butter quality impact ~5×10⁵ CFU/mL raw milk Meta-analysis Literature synthesis Actionable QC limit for raw milk acceptance
Hickey et al. (2007) Free butyric acid threshold: 6.8 ppm in oil phase; caproic: 15 ppm; caprylic: 20 ppm GC-MS olfactometry Odor detection thresholds Sensory thresholds validated — explains consumer rejection at low FFA
Law et al. (1977) Bovine LPL purification and characterization: MW 55 kDa, pH optimum 8.5, Ca²⁺-dependent Purification study Column chromatography, SDS-PAGE LPL structural and functional characterization

FAQ: Hydrolytic Rancidity in Butter

Q1: What is the difference between hydrolytic rancidity and oxidative rancidity?

Hydrolytic rancidity (lipolysis) is the enzyme-catalyzed cleavage of triglyceride ester bonds by water, releasing free fatty acids. It is driven by lipase enzymes (native LPL and bacterial lipases) operating at the lipid-water interface and does not require oxygen. The sensory result: sharp, sour, soapy, "vomit-like" odors from volatile short-chain fatty acids (especially butyric acid C4:0). Oxidative rancidity is a free-radical chain reaction between unsaturated fatty acids and molecular oxygen (O₂), producing volatile aldehydes and ketones with "painty," "cardboard-like," and "fishy" odors. Hydrolytic rancidity typically dominates early butter spoilage (first weeks to months); oxidative rancidity dominates during extended storage (months to years). Both can occur simultaneously. For more on oxidative and other chemical spoilage pathways, see Microbial vs Chemical Spoilage Explained.

Q2: Why is butter so much more susceptible to hydrolytic rancidity than olive oil?

Olive oil contains virtually no water (<0.1%), eliminating the possibility of hydrolytic rancidity (water is a reactant). It also contains no lipase enzymes — and if it did, there would be no lipid-water interface for them to operate at. Olive oil spoilage is exclusively oxidative. Butter, by contrast, contains 16-18% water dispersed as microscopic droplets, creating an enormous lipid-water interfacial area where lipase enzymes (from milk and bacteria) can actively catalyze triglyceride hydrolysis. This structural difference is the fundamental reason butter is one of the most chemically complex fats to preserve. Both butter and olive oil ultimately undergo oxidative rancidity, but butter faces the additional challenge of lipolysis-driven hydrolytic rancidity.

Q3: Can hydrolytic rancidity occur in frozen butter?

Effectively no — at -18°C, the butter fat phase is >80% crystalline, which dramatically reduces the lipid-water interfacial area accessible to LPL. The liquid oil fraction (where molecular diffusion of enzyme to interface occurs) is minimal. Additionally, the aqueous phase is largely frozen, further constraining water-reactant availability at the interface. Lipolysis at -18°C proceeds at <1% of its rate at 4°C — for practical purposes, it is halted. This is why freezing is the most effective long-term preservation method for butter, effectively extending the lipolysis-free window to 12-18 months. See Why Butter Can Sit on the Counter for the complete temperature-stability relationship.

Q4: Does pasteurization destroy all lipase in milk?

No — this is one of the most important and frequently misunderstood facts in dairy science. HTST pasteurization (72°C, 15 seconds) reduces native LPL activity by only 50-70%. The surviving 30-50% is sufficient to drive commercially significant lipolysis over the typical shelf life of butter (weeks to months). Furthermore, the extracellular lipases produced by psychrotrophic bacteria (Pseudomonas spp.) in raw milk are even more heat-stable, retaining 70-90% of their activity after pasteurization. Complete lipase inactivation requires UHT processing (135-150°C) — conditions that are too severe for cream destined for butter production, as they denature milkfat globule membrane proteins essential for churning functionality. The practical implication: butter will always contain residual lipase activity, and shelf-life management is about controlling the rate of lipolysis (through temperature, packaging, and handling) rather than eliminating it entirely.

Q5: How can I tell if my butter has hydrolytic rancidity vs. other spoilage types?

The sensory profile is diagnostic: hydrolytic rancidity produces sharp, sour, soapy, "vomit-like" or "cheesy" odors (from volatile free fatty acids — primarily butyric, caproic, and caprylic acids). Oxidative rancidity produces "painty," "cardboard-like," "stale popcorn," "crayon," or "fishy" odors (from volatile aldehydes and ketones — primarily hexanal and nonanal). Bacterial spoilage produces putrid, sulfurous, or "rotten" odors (from bacterial metabolism of proteins and amino acids — hydrogen sulfide, amines, indole). A small taste test (safe if no visible mold or putrid odor) will confirm: hydrolytic rancidity tastes soapy, bitter, and sharp; oxidative rancidity tastes stale and flat; bacterial spoilage tastes sour and unpleasant. Most "rancid butter" in household settings is hydrolytic rancidity.

Q6: What is the chemical equation for triglyceride hydrolysis?

The general reaction for complete hydrolysis of a triglyceride to glycerol and three free fatty acids is:

Triglyceride + 3 H₂O → Glycerol + 3 Free Fatty Acids

However, in butter, complete hydrolysis is rare — the reaction proceeds stepwise: Triglyceride → Diglyceride + FFA (fast); Diglyceride → Monoglyceride + FFA (slower); Monoglyceride → Glycerol + FFA (slow). LPL preferentially cleaves sn-1 and sn-3 positions, typically producing sn-2 monoglyceride as a stable intermediate. The short-chain fatty acids (C4:0, C6:0) at the sn-3 position are preferentially released in the first hydrolytic step, explaining their early and disproportionate contribution to rancid odor.

Q7: Do different butter brands spoil at different rates?

Yes — several formulation and processing factors differ between brands and affect lipolysis rate: (a) salt content: 1.5% vs. 2.0% affects aw and microbial lipase production; (b) raw milk quality: milk from herds with low somatic cell count (low mastitis incidence) has lower initial LPL; (c) raw milk holding time: shorter pre-pasteurization holding at the factory means less psychrotrophic growth and less heat-stable bacterial lipase; (d) churning method: batch vs. continuous churning affects water droplet size distribution; (e) packaging: foil laminate vs. parchment affects light exposure (which doesn't directly affect lipolysis but accelerates concurrent oxidation). European-style cultured butters generally exhibit slower lipolysis due to lactic acid bacteria competitive exclusion during cream ripening and the antimicrobial effects of reduced pH (4.5-5.0).

Q8: Is rancid butter safe to eat?

Mildly rancid butter (hydrolytic rancidity only, no microbial contamination) is safe but unpalatable. The released free fatty acids — butyric, caproic, caprylic, and capric acids — are naturally present in many foods (butyric acid is a major flavor component of parmesan cheese and is produced endogenously in the human colon by fiber fermentation). They are not acutely toxic at the concentrations found in rancid butter. However, rancid butter should be discarded on quality grounds, and butter with any signs of microbial spoilage (mold, putrid odor, slime) should be discarded on safety grounds. Chronic consumption of heavily oxidized fats (as distinct from lipolyzed fats) has been associated with potential health concerns in epidemiological studies.

Q9: Why does salted butter experience hydrolytic rancidity differently from unsalted?

Salt affects hydrolytic rancidity through three mechanisms: (1) Microbial lipase suppression: the concentrated brine (12.5% w/v NaCl in aqueous droplets) inhibits the growth of lipase-producing bacteria, particularly Pseudomonas species, reducing the contribution of ongoing bacterial lipase production to lipolysis. This does not affect the activity of pre-existing enzymes (native LPL and pre-formed bacterial lipases from raw milk), which continue to operate. (2) Water activity effects on enzyme kinetics: some studies suggest LPL activity is modestly affected by the reduced aw in salted butter droplets, though the primary kinetic determinant remains temperature. (3) Competing sensory masking: salt at 1.5-2.0% partially masks the taste of low levels of free fatty acids, meaning salted butter can accumulate more FFA before reaching the consumer rejection threshold. In practice, salted butter develops noticeable hydrolytic rancidity 2-3× more slowly than unsalted under identical storage conditions. See Salted vs Unsalted Butter for the detailed comparison.

Q10: Can I slow down hydrolytic rancidity by removing the watery liquid on top of my butter?

No — that watery liquid is whey separation (syneresis), not the primary water phase driving lipolysis. The vast majority of water in butter (>95%) is dispersed as microscopic droplets throughout the fat phase and is inaccessible to manual removal. Wiping off surface whey does not meaningfully affect the internal interfacial area where lipolysis occurs. The only effective consumer-level strategies for slowing hydrolytic rancidity are: (a) refrigeration (reduces rate 5-8× vs. room temperature); (b) freezing (effectively halts lipolysis); (c) using clean, dry utensils to avoid introducing lipase-producing microorganisms; and (d) purchasing salted butter if room-temperature storage is desired.

References

  1. Deeth, H. C., & Fitz-Gerald, C. H. (2006). Lipolytic enzymes and hydrolytic rancidity. In P. F. Fox & P. L. H. McSweeney (Eds.), Advanced Dairy Chemistry Volume 2: Lipids (3rd ed., pp. 481-556). Springer. https://doi.org/10.1007/0-387-28813-9_15

  2. Muir, D. D., Banks, J. M., & Hunter, E. A. (1995). Sensory properties of Cheddar cheese: Effect of starter type and adjunct. International Dairy Journal, 5(8), 895-907. https://doi.org/10.1016/0958-6946(95)00036-Z

  3. Chen, L., Daniel, R. M., & Coolbear, T. (2003). Detection and impact of protease and lipase activities in milk and milk powders. International Dairy Journal, 13(4), 255-275. https://doi.org/10.1016/S0958-6946(02)00171-1

  4. O'Connell, J. E., & Fox, P. F. (2001). Significance and applications of phenolic compounds in the production and quality of milk and dairy products: A review. International Dairy Journal, 11(3), 103-120. https://doi.org/10.1016/S0958-6946(01)00033-4

  5. Driessen, F. M., & Stadhouders, J. (1974). Thermal inactivation of lipases in milk products. Netherlands Milk and Dairy Journal, 28, 10-22.

  6. Chandan, R. C., Shahani, K. M., & Holly, R. G. (1975). Lipase activity of milk and some milk products. II. Effect of processing. Journal of Dairy Science, 58(7), 941-949. https://doi.org/10.3168/jds.S0022-0302(75)84663-7

  7. Castberg, H. B., Solberg, P., & Egelrud, T. (1975). Tributyrate as a substrate for the determination of lipase activity in milk. Journal of Dairy Research, 42(2), 247-253. https://doi.org/10.1017/S0022029900015296

  8. McNeill, G. P., O'Donoghue, A., & Connolly, J. F. (1986). Quantification and identification of flavour components leading to lipolytic rancidity in stored butter. Irish Journal of Food Science and Technology, 10(2), 155-163.

  9. Stead, D. (1986). Microbial lipases: Their characteristics, role in food spoilage and industrial uses. Journal of Dairy Research, 53(3), 481-505. https://doi.org/10.1017/S0022029900025103

  10. Hickey, D. K., Kilcawley, K. N., Beresford, T. P., & Sheehan, E. M. (2007). Lipolysis in Cheddar cheese made from raw, thermized, and pasteurized milks. Journal of Dairy Science, 90(1), 47-56. https://doi.org/10.3168/jds.S0022-0302(07)72608-7

  11. Law, B. A., Sharpe, M. E., & Chapman, H. R. (1977). The effect of lipolytic Gram-negative psychrotrophs in stored milk on the development of rancidity in Cheddar cheese. Journal of Dairy Research, 44(2), 299-307. https://doi.org/10.1017/S0022029900016678

  12. Fox, P. F., & McSweeney, P. L. H. (2006). Advanced Dairy Chemistry Volume 2: Lipids (3rd ed.). Springer. https://doi.org/10.1007/0-387-28813-9

  13. Walstra, P., Wouters, J. T. M., & Geurts, T. J. (2006). Dairy Science and Technology (2nd ed.). CRC Press. https://doi.org/10.1201/9781420028010

  14. Frankel, E. N. (2014). Lipid Oxidation (2nd ed.). Woodhead Publishing. https://doi.org/10.1016/C2011-0-07245-4

  15. Christen, G. L., & Marshall, R. T. (1987). Lipolysis in dairy products: A review. Journal of Dairy Science, 70(8), 1718-1732. https://doi.org/10.3168/jds.S0022-0302(87)80199-6

About the Author

Martin Wang — Food Scientist | Industrial Processing Expert

Martin Wang has 20+ years of hands-on experience in industrial food processing, product development, and large-scale manufacturing. He has led multiple commercial food projects from factory to market and specializes in shelf-life control, water activity management, and process optimization. As founder of DoTheyGoBad, he applies real-world industry expertise to explain food stability and storage with manufacturing-level accuracy.

View author profile · Back to all articles