KM-73A Food-Grade Silicone Antifoam Emulsion is metered into beet sugar extraction lines where raw juice produces persistent foam from saponins, pectin fragments, and denatured beet proteins released during countercurrent diffusion. The emulsion is fed after cold liming and before the first-effect evaporator feed tank. Addition rates of 2 ppm to 10 ppm active polydimethylsiloxane relative to raw juice mass are typical for diffuser overheads and evaporator feed streams. Injection uses a diaphragm dosing pump with discharge pressure of 0.5 bar to 2.0 bar. The diluted emulsion remains effective in raw juice at pH 5.5 to 7.0 and at feed temperatures up to 85 °C. The presence of suspended solids does not require pre-filtration. Foam carryover from the vapour separator is reduced. Heat-transfer surfaces in mechanical vapour recompression falling-film evaporators remain cleaner between cleaning cycles. Foam reduction is verified during dosing trials by the Ross-Miles method according to ASTM D1173. Compliance is referenced to FDA 21 CFR 173.340 and EU Regulation (EC) No 1333/2008 Annex II for E900. Finished streams are white beet sugar, molasses, and pelletized beet pulp. The emulsion should not be dosed upstream of carbonatation when excess nonionic emulsifier loading could increase filter pressure drop. Published data for KM-73A in diffuser-specific dosing locations is limited; therefore, the injection point is validated by foam height sampling rather than assumed from generic sugar mill data.

What Limits KM-73A Addition in Submerged Citric Acid and Fungal Amylase Fermentations?

Submerged aerobic fermentation of Aspergillus niger for citric acid monohydrate generates voluminous foam from extracellular polysaccharides, mycelial fragments, and pH-dependent protein denaturation. In a 10 m³ working-volume stirred-tank bioreactor fitted with two Rushton impellers and an air sparge rate of 1.0 vvm, foam rises into the headspace and can blind exhaust filters. KM-73A is added as a sterilized aqueous dilution at 1:10 with deionized water. Terminal sterilization is carried out at 121 °C for 15 min in a stainless-steel pressure vessel. Post-autoclave creaming index is measured; values above 5% by volume indicate unsuitable heat stability for that batch. Initial charge rates range from 30 ppm to 80 ppm active polydimethylsiloxane based on initial working volume. Foam capacitance sensors trigger pulse additions of 5 ppm to 20 ppm active when the headspace foam interface exceeds the control setpoint. Over-addition above 120 ppm active may reduce the volumetric oxygen transfer coefficient kLa by blocking the gas-liquid interface, especially at low impeller power input of 1.5 kW m⁻³. The emulsion is introduced upstream of the air sparger, not into the impeller vortex, to minimize shear-induced droplet size reduction below 10 µm. Droplets below 10 µm can remain dispersed and reduce oxygen transfer rather than spread at the foam lamella. Published data for KM-73A in this specific configuration is limited; therefore, on-site validation against dissolved oxygen probes is required. Compliance for food enzymes and citric acid is governed by FDA 21 CFR 173.340 and EU Regulation (EC) No 1333/2008 Annex II for E900. Finished products are citric acid monohydrate crystals, fungal alpha-amylase, and yeast extract powder. Recovery operations include vacuum filtration and rotary drum filters. Residual silicone in the spent mycelium filter cake can alter ring dryer drying kinetics. A daily CIP cycle with 1% to 2% NaOH at 75 °C removes silicone films from stainless internals. The use of KM-73A does not replace mechanical foam breakers in high-viscosity broths above 800 mPa·s. At pH below 2.0 during citric acid production, the emulsion may show reduced stability; inline dilution with acidified water is avoided in favour of neutral water. Lot-specific Kosher and Halal certification should be verified before use in enzyme products destined for dietary markets.

Whey Protein Concentrate Falling-Film Evaporation with Mechanical Vapour Recompression

Demineralized sweet whey entering a four-effect falling-film evaporator produces foam when the protein content exceeds 12 wt% and the feed temperature reaches 60 °C during preheating. KM-73A is metered into the balance tank at 10 ppm to 30 ppm active silicone relative to feed stream mass. The metering point is after the plate heat exchanger and before the distribution head of the first effect. Continuous dosing is preferred over slug addition because foam collapse in high-viscosity WPC retentate is slower than in raw juice. The diluted emulsion is prepared at 1:20 using 45 °C potable water and held with slow agitation at less than 60 rpm. Excessive agitation accelerates coalescence. Foam-control performance is monitored by differential pressure across the vapour separator; an increase above 8 kPa indicates breakthrough. Proteinaceous foam carryover into the MVR compressor reduces impeller balance and accelerates deposition on vanes. KM-73A addition at the specified range does not alter protein denaturation index or bulk density of spray-dried WPC80, as measured by differential scanning calorimetry denaturation enthalpy and loose bulk density. Compliance references include FDA 21 CFR 173.340 and EU Regulation (EC) No 1333/2008 Annex II for E900. Residual silicone in the final powder is controlled by addition rate and evaporator residence time. Alkaline CIP with 1.5% NaOH at 80 °C is required to remove silicone-protein films from heating surfaces. The emulsion is not appropriate for use in infant formula streams unless a specific regulatory filing confirms the exact residual level. Finished products are WPC80, whey permeate powder, and lactose monohydrate.

Cut leafy greens and carrot sticks handled in recirculating flume water release fine plant cell debris, soluble proteins, and natural saponins that generate stable foam during air-knife dewatering and optical sorting. KM-73A is injected into the flume balance tank at 2 ppm to 5 ppm active silicone relative to water volume. Injection uses a peristaltic metering pump with continuous feedback from a turbidity sensor. Foam control prevents pump cavitation in the main circulation loop and improves the resolution of optical defect detection cameras. A post-rinse stage with 1% to 2% citric acid solution at 4 °C lowers pH and removes surface residues. The dilution water must be potable and free of residual chlorine above 4 ppm because chlorine can destabilize the nonionic emulsion. Residual silicone carryover on the final product falls under FDA 21 CFR 173.340 and requires verification by laboratory extraction and silicon determination by ISO 11885. In flume water, the emulsion is effective at pH 5.5 to 8.0. Operations at pH below 5.0 using peracetic acid sanitizer may form oil-like coalescence on the water surface; the emulsion should be pre-diluted 1:100 before injection under these conditions. Finished products are ready-to-eat salad mixes, frozen cut leafy greens, and fresh-cut carrot coins.

When KM-73A Is Pre-Dispersed into Continuous Snack Fryer Oil at 175 °C

KM-73A is water-dilutable and must never be introduced directly into hot fryer oil. Direct injection into oil at 175 °C causes instantaneous water flash and possible operator exposure. The emulsion is first mixed into a sidestream of cooled oil at 50 °C to 60 °C at a ratio of 1:10 and then returned to the fryer oil supply tank. Active silicone addition rates of 1 ppm to 5 ppm based on oil mass are typical in continuous potato chip fryers. Silicone addition at this level suppresses starch-protein foam at the oil surface and reduces oil mist above the fryer hood. Over-addition above 10 ppm active is not recommended because residual polydimethylsiloxane may appear in heat exchanger fouling deposits and oil smoke point may shift. The frying system includes a continuous filter and heat exchanger; KM-73A passes through the filter without adsorption on sheet filter media. Compliance with FDA 21 CFR 173.340 applies to dimethylpolysiloxane as a defoaming agent in frying oil. Finished products are potato chips, corn-based snacks, and batter-coated extruded snacks. Oil turnover rates and fried food silica residues should be monitored when multiple antifoam sources are present.

Liquid Egg Yolk Pasteurization Produces Thermally Stable Foam Loadings in Spray Dryer Feed

Whole egg and egg yolk streams pumped through plate heat exchangers at 65 °C to 70 °C develop heat-stable foam due to lipoprotein denaturation and air incorporation from diaphragm pumps. KM-73A is dosed at 5 ppm to 15 ppm active silicone relative to liquid egg mass in the holding tank after pasteurization and before high-pressure spray dryer feed. The emulsion is diluted 1:50 in 15 °C potable water prior to injection. Addition reduces foam in the spray dryer feed line and prevents filter blockage in the atomizer nozzle circuit. It is not dosed into separated egg white streams where foaming performance for bakery use is critical. Compliance with FDA 21 CFR 173.340 is applicable; EU import requires E900 listing under EU Regulation (EC) No 1333/2008 Annex II. Silicone residue in egg powder is monitored by silicon content using ISO 11885. The emulsion should not be combined with alkaline phosphate buffer at pH above 9.0 because emulsion instability may produce oil separation. Finished products are whole egg powder, egg yolk powder, and frozen liquid egg for bakery supply chains.