256 Produce Degradation: Reaction Pathways and their Prevention
recommend that patients taking bifidobacteria also supplement with fructo-oligosac-
charides. Several trials have used 8 g/d. However, a review of the research has
suggested that 4 g/d appears to be enough to significantly increase the amount of
bifidobacteria in the gut (Gibson, 1998). Acidophilus and bifidobacteria also have
the ability to manufacture B-vitamins, including niacin, folic acid, biotin, and vitamin
B 6 (Bengmark, 1996).
Other health benefits associated with consumption of probiotic microorganisms
in fermented foods are stabilization of Crohn’s disease, stimulation of intestinal
peristalsis, decreased fecal enzyme activity, activity against Helicobacter pylori,
inhibition of some cancers, reduction of serum cholesterol, and reduction in hyper-
tension (Hartley et al., 2001). Because of their health benefits, probiotics have
therefore been postulated to have either a preventive or a palliative role in several
health conditions, including diarrhea, vaginitis, yeast infection, canker sores, Crohn’s
disease (Saccharomyces boulardii), eczema, food allergies, HIV/AIDS (Sacchara-
myces boulardii), immune function, infections, ulcerative colitis, and chronic can-
didiasis (Hartley et al., 2001).
8.10.6 USE OF ADDITIVES
Additives are organic or inorganic compounds added to fruits and vegetables either
whole or minimally processed to maintain the wholesomeness and palatability of
the produce (Salunkhe, 1974; Salunkhe et al., 1991). Additives are classified into
approximately seven groups. Theses include (1) colors; (2) preservatives; (3) acids,
antioxidants, and mineral salts; (4) vegetable gums, emulsifiers, and stabilizers;
(5) mineral salts and anti-caking agents; (6) flavor enhancers; and (7) disinfectants.
Table 8.5 summarizes the common additives used in fruits and vegetables. Many
people feel that additives are sometimes used when there is no real need for them,
but most additives have a useful role. In fruits and vegetables, for example, preser-
vatives help to prevent spoilage and prolong the shelf life of the produce. Antioxi-
dants inhibit oxidative degradation of essential nutrients such as vitamin C, while
antimicrobials (antibiotics, fungicides, sulfite and sulfur dioxide, chlorine, chlorine
dioxide, sodium thiosulfate, trisodium phosphate, surfactants, humectants, and lactic
and acetic acids) inhibit the growth of bacteria and fungi. Proteolytic enzymes help
to inhibit enzymatic browning.
Apart from protecting the produce from physical deterioration, some additives
have shown beneficial effects in retaining some nutrients. The blanching of cabbage
in hot water containing sulfite results in a product with a higher vitamin C content
than when it is blanched in plain water (Salunkhe, 1974). Sulfites also “set” the
green color in green vegetables and protect them from becoming discolored when
blanched with hot water (Salunkhe, 1974). Despite their benefits in preserving foods,
additives have been associated with some negative effects, such as allergic reactions
in some people to some of the additives, particularly sulfites. Some nutrients
(e.g., thiamin) might also be lost in the presence of some additives. Therefore, the
Food and Drug Administration of the United States has banned the use of sulfur-
based additives in fruits and vegetables.