Sweet whey powder (SWP)

Sweet whey powder is produced by drying the whey obtained from rennet-induced (“sweet”) coagulation of milk in cheesemaking. Compared with acid whey, it has a higher pH, a different mineral profile, and a milder, sweeter flavor. As a food ingredient, it reconstitutes readily, provides bulk primarily via lactose, and contributes a moderate amount of functional whey proteins.

Caloric value (dry product, 100 g)
Approximately 360–390 kcal per 100 g (typical ≈ 370 kcal/100 g; varies with moisture, protein, and ash).

Average composition (indicative, per 100 g)
Lactose: ~70–75 g (predominant).
Total protein: ~11–14 g (whey proteins: β-lactoglobulin, α-lactalbumin, serum albumin, immunoglobulins).
Ash/minerals: ~8–10 g (Na, K, Ca, P, Cl in a sweet-whey pattern).
Fat: ~0.5–2 g (residual).
Moisture: ≤5%.
Vitamins/minors: trace water-soluble vitamins; small organic acids; solution pH typically ~6.2–6.6.

Manufacturing process (outline)
Whey separation at the dairy, clarification/filtration, and standardization.
Thermal treatment (pasteurization) and concentration by evaporation or membranes (UF/RO/NF, depending on line design).
Spray-drying; optional agglomeration/instantizing to improve wetting and dispersion.
Variants include partially demineralized or delactosed wheys and higher-protein cuts beyond standard SWP; functional fractions can be produced for specific applications.

Technological and sensory properties
Solubility: high; agglomerated powders reduce lumping and improve dispersibility.
Hygroscopicity: marked due to amorphous lactose → risk of caking at high RH; barrier packaging and, where permitted, flow aids help.
Browning/flavor: lactose drives Maillard reactions during baking/cooking (color and caramel notes); long storage can produce non-enzymatic browning.
Lactose crystallization: desirable for texture in some confections, but unmanaged crystallization can cause sandy “grit.”
Protein functionality: moderate emulsifying/foaming relative to concentrates (WPC) or isolates (WPI), yet adequate in many formulas.

Food applications
Bakery/pastry: color development, volume, and moisture in cookies, cakes, wafers.
Confectionery: milk caramels, fillings, bars; body and crystallization control.
Powdered beverages and desserts: base of lactose/protein for instant mixes, cappuccino beverages, soft-serve mixes.
Recombined dairy: support for yogurts and fresh cheeses (as a co-ingredient), reconstituted milks.
Cooked meats/processed foods (where permitted): binder and water-holding aid.
Infant nutrition: typically uses demineralized, purpose-standardized whey rather than common SWP.

Nutrition and health
Energy is dominated by lactose; protein is moderate in quantity but high in biological value (whey proteins rich in essential amino acids, notably leucine). Individuals with lactose intolerance should limit or avoid SWP. Total fat is low; when present it is mainly dairy SFA with small MUFA/PUFA fractions—overall lipid impact per 100 g powder is modest.

Quality and specifications (typical themes)
Moisture ≤5%.
Wettability/instant properties: aligned with application (instant versus standard).
Scorched particles: within specified class for spray-dried powders.
Ash and conductivity: consistent with sweet whey (lower in demineralized variants).
Titratable acidity and pH: coherent with “sweet” profile.
Microbiology: total count, coliforms, Staphylococcus aureus, and spores; tighter criteria for sensitive uses.
Contaminants: metals/pesticides within limits; no CIP residues; no foreign matter.
Organoleptic: clean dairy aroma, no burnt/oxidized notes; uniform cream-straw color.

Storage and shelf life
Store cool and dry, protected from light and odors, in barrier packaging; reseal tightly after opening. Limiting aw and ambient RH helps prevent caking and cold-storage Maillard. With multilayer sacks or lined drums, typical shelf life is 12–24 months, depending on moisture, temperature, and granulation/agglomeration.

Allergens and safety
Milk-derived: mandatory allergen labeling applies. Lactose content is usually significant. Prevent cross-contact with other allergens in multiproduct facilities via robust HACCP and GMP.

Troubleshooting
Caking/lumping in storage: excessive RH or temperature; improve packaging barrier, add secondary desiccants, or lower final moisture.
Poor solubility/excess foam: thermal damage or entrained air; retune spray-dry and agglomeration parameters.
Grittiness in confections: uncontrolled lactose crystallization; adjust solids, cooling, and seed crystals.
“Cooked”/oxidized notes: over-heating or long storage; correct thermal profile and tighten FIFO rotation.
Instability in acidic beverages: protein precipitation at low pH; use stabilizing systems or more acid-stable fractions.

Sustainability and supply chain
Whey has high BOD/COD; valorizing it as powder reduces effluent loads and environmental impact. Membrane pre-concentration (RO/UF) and heat-recovery on evaporators/spray-dryers improve energy efficiency. Farm/dairy traceability and animal-welfare assurances are increasingly requested in many markets.

Conclusion
Sweet whey powder is a cost-effective, versatile ingredient that combines lactose bulk, moderate high-quality protein, and useful color/flavor development in heat applications. Careful control of moisture, packaging, and thermal profile maximizes solubility, stability, and sensory quality across a broad range of uses.

Mini-glossary of lipid acronyms (English)
MUFA — MonoUnsaturated Fatty Acids: Generally favorable for heart and lipid profile (e.g., oleic acid).
PUFA — PolyUnsaturated Fatty Acids: Include omega-3 and omega-6; beneficial, but keep a balanced omega-6:omega-3 ratio.
SFA — Saturated Fatty Acids: To moderate; impact depends on overall diet and the replacement nutrient.
ALA/EPA/DHA (omega-3) — Alpha-linolenic acid / Eicosapentaenoic acid / Docosahexaenoic acid: Support heart and brain health, with stronger evidence for EPA/DHA.
TFA — Trans Fatty Acids: To avoid; associated with increased cardiovascular risk.
MCT — Medium-Chain Triglycerides: Rapidly absorbed; useful in specific contexts, but still count toward total calories.