Membrane filtration systems for food and beverage industry
Where single or multiple evaporators have been used in the past to concentrate fruit and vegetable juices, reverse osmosis is now an alternative that is much more efficient with energy, time, space, yield, product quality and cost. Often a membrane filtration system will be placed before an evaporator to increase evaporator efficiency. This is called preconcentration. A major advantage of membrane filtration over more traditional separation methods such as vacuum or pressure filtration is that with the option of diafiltration, color is actually gained rather than lost.
A wide variety of vegetable juices have been successfully clarified and concentrated using membrane filtration. These include but are not limited to:
- Onion Juice
- Carrot Juice
- Celery Juice
- Cucumber Juice
- Leek Juice
- Green Pepper Juice
- Aloe Vera Juice
- Garlic Juice
Fruit juice processing is among the most common applications of membrane filtration. Just a handful of the fruit juices that have been efficiently clarified and concentrated by membrane filtration are:
- Grapefruit Juice
- Strawberry Juice
- Orange Juice
- Peach Juice
- Pineapple Juice
- Apple Juice
- Pear Juice
- Tomato Juice
Concentration and deashing of pork , bone or beef gelatin
Meat brine clarification for bacteria removal and brine re-use
Vegetable and plant proteins such as soy, canola and oat
- After removing vegetable/plant matter with a pre-filter MF removes bacteria and sends the permeate to be concentrated for protein recovery.
Soy Protein Isolate
- The recovery of soy protein includes two options for processing: the food process and the polymer process. The difference between the two is that the food process requires more hydrolyzation of the proteins which results in smaller protein fragments which requires a different filter.
Specialty Ethnic Foods Food Ingredients/Flavors
- Food coloring: reduce COD, remove impurities and salts
Process Water Reclamation
- Clarification of Beer
- Yeast and any other suspended solids are cleared from the beer
- Dealcoholization of Beer
- Malt beverage clarification/decolorization
- Dealcoholizatlon of Wine
- Soy Milk Whey
- Soy Protein Isolate
- Starch/Gluten Recovery Tomato Sauce
- By using a combination of microfiltration and reverse osmosis, valuable byproducts can be drawn from tomato sauce. Carrot Juice Celery Juice Maple Syrup
- MF can clarify honey by removing large proteins. UF can remove naturally occurring bacteria in honey, making it suitable for end uses which have previously not been an option due to the bacteria.
- Beef Stick Water
- Surimi Wash Water
- Gelatine Production
- Potato Starch Recovery
- Dextrose Clarification
- Corn Syrup Clarification
- Malto Dextrin Clarification
- Fructose Clarification
- Egg White Concentration
- See Egg White RO. 30% retentate solids with spiral.
- Used as a fat substitute.
- Whole Egg Concentration
- See Whole Egg UF. More than 2x concentration of whole egg mélange is possible. 20% skim milk added.
- Porcine Bovine Blood Plasma
- Chicken Blood
Starch & Sweetener Industry
The starch and sweetener industry has seen membrane filtration replace traditional separation methods such as filter presses and rotary vacuum filters in a number of process steps. The primary benefits are elimination of handling/disposal of diatomaceous earth (kieselguhr) and increase in product yields. These include:
- Clarification of corn syrups such as dextrose and fructose
- Concentration of starch wash water
- Dextrose enrichment
- De-pyrogenation of dextrose syrup
- Fractionation/concentration of steep water
Both the cane and beet sugar industries have used age old methods such as liming and flocculation to clarify the raw juice and remove impurities such as waxes, dextrans and gums before sending the juice to the refining step for evaporation and crystallization.
Membrane filtration can be used to clarify the raw juice off the primary clarifiers, thereby eliminating many environmental problems and improving the quality and yield of the juice.
Cross-flow membrane filtration technology is quickly gaining global acceptance as an important manufacturing step in many process industries worldwide. The ability to produce very specific separations / purifications at low or ambient temperatures often make membrane filtration a much more cost-effective technology than more conventional methods such as rotary vacuum filtration or filter presses.
Membrane filtration is a pressure driven technology with pore sizes ranging from 100 molecular weight to 5 microns. The technologies included in membrane filtration are: Reverse Osmosis RO, Nanofiltration NF, Ultrafiltration UF, and Microfiltration MF.