Firming of Canned Vegetables by Addition of Lactose

Blanched carrots, green beans, and peas were retorted at 121°C in 2% NaCl brine containing variable amounts of dissolved lactose. After 37 and 68 days, hardness of the canned vegetables was tested by Instron. Increasing lactose content correlated significantly with average hardness of peas (r = 0.94 and 0.96, respectively), beans (r = 0.81 and 0.91), and to a lesser degree, carrots (r = 0.71 and 0.37). All products from brines containing 8% or more lactose showed higher average hardness than those containing less or no lactose. The increase in hardness was noticeable to an untrained sensory panel. Samples packed in 8–15% lactose brines were ranked significantly higher in firmness than those canned with 5% or less lactose.