Showing papers by "Malcolm C. Bourne published in 1973"

Preservation of carrots by lactic acid fermentation

Abstract: Whole, sliced and shredded Chantenay carrots were subjected to lactic acid fermentation in brines comprised of 1.5, 2.0, 2.5, 3.0% sodium chloride concentrations. One series was fermented by the naturally occurring microflora of the raw carrot and a second series was fermented by a mixed culture of homofermentative and heterofermentative lactic acid bacteria. Although the latter inocula significantly reduced the lag phase of early acid formation, all samples following 21 days incubation attained total acid values in excess of l%, expressed as lactic acid. The volatile-to-nonvolatile acid ratios showed that the lactic acid fermentation of carrots arose as the result of a dominant homofermentative flora. Mild heat treatment of the high-acid product at 71°C produced no adverse changes in color or texture. The resulting flavor of the fermented carrots was judged to be a pleasant composite of carrot, salt and acidic characteristics and most of the crisp texture of the raw carrot was retained.

Use of the penetrometer for deformation testing of foods

Abstract: The cone of a penetrometer is replaced by a flat, light-weight plastic horizontal disc which is allowed to compress an article of food for 5 set, after which a reading is taken from the dial of the instrument. Next a weight is placed on the upper end of the vertical shaft that carries the disc and the food is compressed again for 5 set, after which a second reading is taken from the dial. The difference between the two dial readings gives the deformation to the nearest 0.1 mm. Examples of its use on tomatoes and marshmallows are given. The test works well on foods that are deform able, but is not recommended for rigid foods because of lack of precision.