Factory Kitchen: Ten Industrial Techniques That Convert, Dry, Preserve and Package Food

The amylolytic process turns starch into sugar through acids or enzymes such as amylase. Beer uses malting to trigger it, sake uses the mold Aspergillus oryzae and tapai uses Saccharomyces cerevisiae yeast, and industry uses hydrolysis to maximize glucose from starch.

Extrusion forces a soft mix through a shaped die, driven by a rotating screw inside a barrel, and blades cut the result to size. Pasta, croutons and sausages are extruded without cooking, while breakfast cereals, snacks and textured vegetable protein are made by extrusion cooking.

Spray drying makes a dry powder from a liquid by dispersing it into droplets of roughly ten to five hundred micrometers in hot gas. It suits heat sensitive foods and materials needing a consistent fine particle size; freeze drying, drum drying and pulse combustion drying are alternatives.

Microencapsulation surrounds tiny particles or droplets with a coating to form small capsules, with walls of materials such as gelatin, sodium alginate or maltodextrin. Flavor encapsulation is a particularly common food use, and modern capsules may have crystal, emulsion or multi-wall cores.

Vacuum frying happens in a sealed chamber at reduced pressure, so food fries at around 130 degrees Celsius instead of roughly 170. The lower temperature helps food keep its natural color and flavor and reduces acrylamide formation and oil absorption. It is used mainly for fruit chips in Southeast Asia.

Biopreservation uses natural or controlled microbiota, centrally lactic acid bacteria, or the antimicrobial compounds they make to extend shelf life. It works chiefly through organic acids that lower pH, has been used since ancient times, and is regarded as a benign, ecological approach.

Flash pasteurization, also called high-temperature short-time processing, treats perishable beverages such as juices, beer, wine and milk. It keeps color and flavor better than other pasteurization processes. The standard US protocol for flash pasteurizing milk was introduced in 1933.

Retort processing sterilizes sealed containers at about 116 to 121 degrees Celsius under high pressure in a vessel called a retort or autoclave. It reliably kills spoilage organisms, particularly Clostridium botulinum, so food keeps at room temperature in cans or flexible pouches.

Radicidation is a food irradiation application using about 2 to 8 kilograys of ionizing radiation to reduce pathogenic bacteria to undetectable levels without full sterilization. The term also covers 0.1 to 1 kilogray doses that destroy parasites such as tapeworm and trichina in meat.

Boil-in-bag food is sealed in a plastic pouch and heated directly in boiling water. Solid bags hold frozen prepared dishes, perforated bags let water in for grains, and rice is the most common product, usually in a temperature-resistant polypropylene bag.