Sweet potato starch syrup

One of the more recent innovative approaches was to look for new micro-organisms and novel carbohydrate substrates. The early fermentations used sugar beet or cane molasses, various syrups, sweet potato starch or glucose itself and the micro-organism was always an Aspergillus spp. In the early 1930 s it was found that yeasts would produce dtric add from acetate. Since then a variety of yeasts, prindpally Candida spp., has been shown to convert glucose, w-alkanes or ethanol to dtric add with great effidency. 

FIG. 7 Overview of enzymatic hydrolysis of sweet potato starch into glucose syrup. LIQ = Liquefaction, SAC = Saccharification (Bovell-Benjamin et al., 2005). 

The cereal seeds, tubers, starch storage roots, and bean/pea seeds are directly consumed as food in human diet or animal feed and are used as a source of starch. Extracted starch can be used to produce starch derivates or hydrolyzed to produce soluble sugars, food additives, or glucose syrup. Also, extracted starch can be used for other applications in nonfood industries (Nghiem et al. 2011). For example, it is used as a thickener and as a source of renewable raw material for bioethanol production. The major source of starch for the world market is cornstarch holding more than 80 % of the market, but wheat, potato, cassava or tapioca, and to a lesser extent rice and sweet potato starches are also commercialized (Thomsen et al. 2008). 

The GRAS affirmation contained in 21 CFR, Section 184.1444, defines maltodextrins as non-sweet, nutritive saccharide polymers consisting of D-glucosyl units linked primarily with alpha-1,4 bonds and having a DE less than 20. The document has been modified to include maltodextrins derived from potato starch as GRAS.8 In 1992, more than 328 million pounds (149x 106 kg) of maltodextrins and com syrup solids were produced in the United States from various starch sources.9... 

Starch—Starch (as such) is tasteless (not sweet). But starch from any starch source—cereal grains or potatoes—may h)e broken down into its component sugar, either enzymatically or with dilute acids. The most familiar example in the United States is corn syrup (Karol). Complete hydrolysis of starch yields glucose (dextrose), which is sweet. 

Pure-grade m. is crystallized from maltose syrups, produced by enzymatic hydrolysis of liquefied - starches or of soluble ->amyloses. M.-forming enzymes are p-> amylases from higher plants, such as barley malt, extracts from soybean or sweet potatoes or from microorganisms Pseudomonas sp. leading to hydrolyzates of mainly P-m. 

In recent years, the conversion of starch to fructose has become a very important commercial process. High-fructose corn syrup (HFCS) is approximately twice as sweet as sucrose. It is used in soft drinks, canned fruits, lactic acid beverages, juice, bread, ice cream, frozen candies, and so on. HFCS can be obtained from a variety of cereals and vegetables, such as corn, wheat, rice, potatoes, and cassava. Corn is the most important source of HFCS because of low costs and excellent utilities of its by-products, corn meal, oil, gluten, germ, and fiber. 

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