If you have been reading about Water activity and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-09-20. Numbers and descriptions here follow the published literature rather than marketing material.
Whey protein hydrolysate is a dairy ingredient produced when whey proteins are treated with proteolytic enzymes or, less commonly, acid or heat under controlled conditions. The treatment cleaves peptide bonds and yields shorter peptide chains than those found in intact whey protein. The starting material is usually sweet whey or acid whey from cheese manufacture, concentrated by membrane filtration before hydrolysis. The resulting ingredient retains many amino acids from the original protein but differs in molecular size, solubility, and taste profile.
The parent whey proteins include beta-lactoglobulin, alpha-lactalbumin, serum albumin, immunoglobulins, and glycomacropeptide, depending on the whey source. Hydrolysis does not remove these sequences; it fragments them into peptides of varying length. The peptide distribution depends on the enzyme specificity, reaction time, temperature, pH, and enzyme-to-substrate ratio. Because the mixture is heterogeneous, a single molecular weight cannot describe the product. Instead, laboratories report a distribution, often spanning from a few hundred to several thousand daltons.
Whey protein hydrolysate appears in foods and supplements where rapid digestion, low viscosity, or reduced intact-protein content is desired. It is distinct from whey protein isolate and concentrate, which contain largely intact proteins, though hydrolysates can be made from either. In infant formula, extensively hydrolyzed whey is used in some specialty products, while partially hydrolyzed forms appear in other formulations. Human health effects depend on the specific peptide mixture and are not uniform across all hydrolysates.
Enzyme choice influences the peptide size distribution and the resulting functional properties. Some proteases cut at specific amino acid residues, while others act more broadly, so two hydrolysates with the same degree of hydrolysis can differ in peptide sequences. Short peptides are generally more water-soluble and less likely to form gels under heat, although bitterness can increase when hydrophobic residues become exposed. The relationship between peptide length, taste, and bioactivity is an active area of study, and not all proposed effects are established in human trials.
Composition tables often report protein content on a dry basis, ash, moisture, fat, and lactose. Because hydrolysis adds water to peptide bonds, the total mass yield can appear slightly higher than the original protein if residual salts and water are counted. Some products are further processed by ultrafiltration, spray drying, or decolorization, which alters mineral content and flavor. Product labels may distinguish partially hydrolyzed from extensively hydrolyzed whey, but these terms are not always defined by a single numerical threshold across regions.
Whey protein hydrolysate is a dairy ingredient made by treating whey protein with proteases that cleave peptide bonds. The starting material is typically whey protein concentrate or isolate, which contains beta-lactoglobulin, alpha-lactalbumin, and smaller amounts of bovine serum albumin and immunoglobulins. Hydrolysis shortens protein chains into peptides and free amino acids, changing solubility, viscosity, and flavor compared with intact whey protein. The extent of cleavage is commonly described by degree of hydrolysis, a percentage of broken peptide bonds relative to total bonds.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Whey hydrolysate; hydrolyzed whey protein | Abbreviations such as WPH appear in ingredient lists |
| Appearance | Off-white to light cream powder | Color can vary with starting whey and drying method |
| Solubility class | Highly soluble in water | Short peptides often dissolve more readily than intact whey protein |
| Typical storage temperature | 15–25 °C | Cool, dry conditions limit moisture uptake and browning reactions |
| Typical analytical method | Size-exclusion chromatography | Used to estimate molecular weight distribution of peptides |
Regulatory treatment of whey protein hydrolysate depends on the country and intended use. In many jurisdictions it is regulated as a food ingredient or food for special dietary use, not as a drug. Labeling rules govern allergen statements, protein content claims, and ingredient names. Some markets have specific rules for infant formula ingredients, where hydrolysates may be used for particular dietary purposes. Regulations generally focus on safety, truthful labeling, and manufacturing standards rather than on therapeutic effects. Scientific questions about specific peptide activities remain an active area of research rather than a settled regulatory category.
Whey protein hydrolysate powders are hygroscopic and can absorb moisture from air. Moisture uptake may lead to caking, reduced flowability, and gradual peptide degradation. Manufacturers typically specify cool, dry storage and sealed packaging to limit these changes. Water activity, rather than water content alone, is often monitored because it better predicts microbial and chemical stability. High temperatures can accelerate Maillard reactions between peptides and residual sugars, altering color and flavor. Exact shelf lives depend on formulation, packaging, and initial moisture, so they are usually determined by product-specific stability testing.
Analytical testing for whey protein hydrolysate focuses on peptide size distribution, degree of hydrolysis, protein content, moisture, ash, and microbiological quality. Size-exclusion chromatography and mass spectrometry can characterize peptide profiles, while Kjeldahl or combustion methods estimate total nitrogen and protein. Amino acid analysis quantifies free and total amino acids. Because peptide mixtures are complex, no single method captures every property, and results can vary between laboratories. Standardized methods and reference materials help improve comparability, but full sequence-level characterization remains uncommon in routine quality control.
Hydrolysates usually contain 70% to 90% protein on a dry basis, with variable ash, fat, and carbohydrate. Solubility in water is generally high over a broad pH range, though bitter notes can appear from exposed hydrophobic peptides. The powder tends to absorb moisture and may brown during prolonged warm storage. Applications span sports nutrition, clinical nutrition, infant formulas, and flavor systems. Regulatory status and labeling rules differ by country. A key open question is whether a given peptide profile reliably predicts functional or sensory behavior across different food matrices.
Whey protein hydrolysate is a dairy ingredient made by breaking peptide bonds in whey proteins. Enzymes such as proteases, or in some processes acid or heat, cleave the protein chains into shorter peptides and free amino acids. The starting material may be sweet whey, acid whey, whey protein concentrate, or whey protein isolate. Because raw materials and reaction conditions differ, the final mixture is not a single uniform substance. Its peptide profile, mineral content, and residual lactose depend on the source and the processing steps used.
Alpha particles were first described in the investigations of radioactivity by Ernest Rutherford in 1899, and by 1907 they were identified as He2+ ions. By 1928, George Gamow had solved the theory of alpha decay via tunneling. The alpha particle is trapped inside the nucleus by an attractive nuclear potential well and a repulsive electromagnetic potential barrier. Classically, it is forbidden to escape, but according to the (then) newly discovered principles of quantum mechanics, it has a tiny (but non-zero) probability of "tunneling" through the barrier and appearing on the other side to escape the nucleus. Gamow solved a model potential for the nucleus and derived, from first principles, a relationship between the half-life of the decay, and the energy of the emission, which had been previously discovered empirically and was known as the Geiger–Nuttall law.
The country had fielded black troops during World War I, but since then had retained them only within the BSAP. A nucleus of airmen existed in the form of the Southern Rhodesian Air Force (SRAF), which in August 1939 comprised one squadron of 10 pilots and eight Hawker Hardy aircraft, based at Belvedere Airport near Salisbury. The occupation of Czechoslovakia by Nazi Germany in March 1939 convinced Huggins that war was imminent. Seeking to renew his government's mandate to pass emergency measures, he called an early election in which his United Party won an increased majority. Huggins rearranged his Cabinet on a war footing, making the Minister of Justice Robert Tredgold Minister of Defence as well. The territory proposed forces not only for internal security but also for the defence of British interests overseas. Self-contained Rhodesian formations were planned, including a mechanised reconnaissance unit, but Tredgold opposed this. Remembering the catastrophic casualties suffered by units such as the Royal Newfoundland Regiment and the 1st South African Infantry Brigade on the Western Front in World War I, he argued that one or two heavy defeats for a white Southern Rhodesian brigade might cause crippling losses and have irrevocable effects on the country as a whole. He proposed to instead concentrate on training white Rhodesians for leadership roles and specialist units, and to disperse the colony's men across the forces in small groups. These ideas met with approval in both Salisbury and London and were adopted.
== Diagnosis == No specific test exists to diagnose polymyalgia rheumatica; many other diseases can cause inflammation and pain in muscles, but a few tests can help narrow down the cause of the pain. Limitation in shoulder motion or swelling of the joints in the wrists or hands, are noted by the doctor. One blood test usually performed is the erythrocyte sedimentation rate (ESR) which measures how fast the patient's red blood cells settle in a test tube. The faster the red blood cells settle, the higher the ESR value (measured in mm/hour), which suggests that inflammation may be present. Many conditions can cause an elevated ESR, so this test alone is not proof that a person has polymyalgia rheumatica. Another test that checks the level of C-reactive protein (CRP) in the blood may also be conducted. CRP is produced by the liver in response to an injury or infection, and people with polymyalgia rheumatica usually have high levels. However, like the ESR, this test is also not very specific. Polymyalgia rheumatica is sometimes associated with temporal arteritis, a condition requiring more aggressive therapy. To test for this additional disorder, a biopsy sample may be taken from the temporal artery.
== See also == List of abbreviations used in medical prescriptions List of medical roots, suffixes and prefixes Medical dictionary Medical slang Abbreviation#Style conventions in English Acronym and initialism#Orthographic styling
Sources: en.wikipedia.org
As of 2017, Canada had hundreds of acres of large-scale commercial hydroponic greenhouses, producing tomatoes, peppers and cucumbers. Due to technological advancements within the industry and numerous economic factors, the global hydroponics market is forecast to grow from US$226.45 million in 2016 to US$724.87 million by 2023.
Difficult or impossible to repair or recondition after wear or damage Outgassing and "sweating" of plasticizers and other chemicals from poorly formulated products Typically not as durable as genuine leather
==== MeSH D12.776.556.579.374 – nonheme iron proteins ==== MeSH D12.776.556.579.374.187 – hemerythrin MeSH D12.776.556.579.374.281 – inositol oxygenase MeSH D12.776.556.579.374.375 – iron-sulfur proteins MeSH D12.776.556.579.374.375.025 – adrenodoxin MeSH D12.776.556.579.374.375.150 – ferredoxin-nitrite reductase MeSH D12.776.556.579.374.375.275 – ferredoxins MeSH D12.776.556.579.374.375.275.450 – molybdoferredoxin MeSH D12.776.556.579.374.375.275.725 – rubredoxins MeSH D12.776.556.579.374.375.637 – iron regulatory protein 1 MeSH D12.776.556.579.374.375.818 – iron regulatory protein 2 MeSH D12.776.556.579.374.375.863 – electron transport complex i MeSH D12.776.556.579.374.375.863.500 – nadh dehydrogenase MeSH D12.776.556.579.374.375.909 – electron transport complex ii MeSH D12.776.556.579.374.375.909.500 – succinate dehydrogenase MeSH D12.776.556.579.374.375.954 – electron transport complex iii MeSH D12.776.556.579.374.375.977 – nitrate reductase (nad(p)h) MeSH D12.776.556.579.374.375.988 – nitrate reductase (nadph) MeSH D12.776.556.579.374.450 – lipoxygenase MeSH D12.776.556.579.374.450.025 – arachidonate lipoxygenases MeSH D12.776.556.579.374.450.025.020 – arachidonate 5-lipoxygenase MeSH D12.776.556.579.374.450.025.025 – arachidonate 12-lipoxygenase MeSH D12.776.556.579.374.450.025.030 – arachidonate 15-lipoxygenase MeSH D12.776.556.579.374.687 – retinal dehydrogenase MeSH D12.776.556.579.374.925 – tyrosine 3-monooxygenase
Fentanyl and fentanyl analogues can be qualitatively detected in drug samples using commercially available fentanyl testing strips or spot reagents. Following the principles of harm reduction, this test is to be used directly on drug samples as opposed to urine. To prepare a sample for testing, approximately 10 mg of the drug should be diluted into 1 tsp (5 mL) of water. Research in Dr. Lieberman's lab at the University of Notre Dame has reported false positive results on BTNX fentanyl testing strips with methamphetamine, MDMA, and diphenhydramine. The sensitivity and specificity of fentanyl test strips vary depending on the concentration of fentanyl tested, particularly from 10 to 250 ng/mL.
=== Protein-protein interactions === O-GlcNAcylation of a protein can alter its interactome. As O-GlcNAc is highly hydrophilic, its presence may disrupt hydrophobic protein-protein interactions. For example, O-GlcNAc disrupts Sp1 interaction with TAFII110, and O-GlcNAc disrupts CREB interaction with TAFII130 and CRTC. Some studies have also identified instances where protein-protein interactions are induced by O-GlcNAc. Metabolic labeling with the diazirine-containing O-GlcNDAz has been applied to identify protein-protein interactions induced by O-GlcNAc. Using a bait glycopeptide based roughly on a consensus sequence for O-GlcNAc, α-enolase, EBP1, and 14-3-3 were identified as potential O-GlcNAc readers. X-ray crystallography showed that 14-3-3 recognized O-GlcNAc through an amphipathic groove that also binds phosphorylated ligands. Hsp70 has also been proposed to act as a lectin to recognize O-GlcNAc. It has been suggested that O-GlcNAc plays a role in the interaction of α-catenin and β-catenin.
Sources: en.wikipedia.org
Hybrids are offspring resulting from the breeding of two genetically distinct individuals, which usually will result in a high degree of heterozygosity, though hybrid and heterozygous are not synonymous. The deliberate or accidental hybridizing of two or more species of closely related animals through captive breeding is a human activity which has been in existence for millennia and has grown for economic purposes. Hybrids between different subspecies within a species (such as between the Bengal tiger and Siberian tiger) are known as intra-specific hybrids. Hybrids between different species within the same genus (such as between lions and tigers) are known as interspecific hybrids or crosses. Hybrids between different genera (such as between sheep and goats) are known as intergeneric hybrids. Natural hybrids will occur in hybrid zones, where two populations of species within the same genera or species living in the same or adjacent areas will interbreed with each other. Some hybrids have been recognized as species, such as the red wolf (though this is controversial). Artificial selection, the deliberate selective breeding of domestic animals, is being used to breed back recently extinct animals in an attempt to achieve an animal breed with a phenotype that resembles that extinct wildtype ancestor. A breeding-back (intraspecific) hybrid may be very similar to the extinct wildtype in appearance, ecological niche and to some extent genetics, but the initial gene pool of that wild type is lost forever with its extinction.
== Cause == There are two genetic traits linked to feline cutaneous asthenia. One comes from a dominant allele, while the other comes from a recessive. Both result in similar pathology. Cats with the autosomal dominant form of feline cutaneous asthenia package type I collagen poorly. Collagen is a major component in skin tissue and in tendons. While scientists originally suspected that the problem lay in the production of the type I collagen molecule, it is now known that type V collagen is the molecule which is incorrectly produced. Although scientists do not know exactly how, many suspect that type V collagen assists in packaging type I collagen. Collagen fibrils are often abnormally sized and have unusually large amounts of space between them. The dermis is thinned because of this. In heterozygous cats, normal and abnormal fibrils often exist inside of the same collagen fiber. Homozygous cats are not likely to survive for very long. The autosomal recessive form of feline cutaneous asthenia results in a deficiency of procollagen peptidase or a structural abnormality at its cleavage site. Procollagen peptidase is an enzyme necessary for the post-translational modification of procollagen into collagen. Because of the abnormalities in the formation of collagen fibrils, affected cats produce twisted collagen ribbons, rather than the normal collagen cylinders one would expect to find.
Devro plc is a multinational company with a registered office in Moodiesburn, Chryston, Scotland which manufactures and distributes goods derived from collagen, principally Sausage casings, a product in which it is the world leader. The firm also produces films, casings, and other specialised collagen products for use in the healthcare and cosmetics industries. The company was acquired by SARIA in 2023.
=== Altered glycan theory === According to this theory, the effector function of the immune response is mediated by the glycans (polysaccharides) displayed by the cells and humoral components of the immune system. Individuals with autoimmunity have alterations in their glycosylation profile such that a proinflammatory immune response is favored. It is further hypothesized that individual autoimmune diseases will have unique glycan signatures.
== Overview == Source Filmmaker is a tool for animating, editing and rendering 3D animated videos using assets from most games which use the Source engine, such as sounds, models, and, backdrops. SFM also allows for the creation of still images, art, and posters. SFM contains three different user interfaces and a "work camera" for previewing an active scene. The three interfaces are used for creating clips, controlling animation, and making fine-tuned adjustments, which include:
Sources: en.wikipedia.org
It is made from whey, a byproduct of cheese or casein production, or from whey protein concentrate or isolate. Enzymes break the intact whey proteins into shorter peptides. The final composition depends on the starting whey and the hydrolysis conditions.
No. Whey protein isolate is a purified intact protein, while hydrolysate has been enzymatically cleaved into smaller peptides, and hydrolysate can be produced from isolate or concentrate. The two ingredients differ in molecular size, taste, and functional behavior.
Hydrolysis cleaves proteins but does not necessarily remove lactose, which is a sugar. It can reduce the size of allergenic proteins, yet residual peptides may still trigger reactions in sensitive individuals. Allergen status depends on the extent of hydrolysis and must be assessed for each product.
Hydrolysate has undergone enzymatic cleavage of peptide bonds, while isolate is largely intact protein. Both can originate from the same whey stream, but hydrolysis changes peptide size, solubility, taste, and allergenicity testing outcomes. The two ingredients are not interchangeable in every formulation.