Potato Arabinogalactan Acts as Prebiotics by A Simple Extraction

The effect of the extracting procedures for potato pulp arabinogalactan were investigated on the growth of gut-microflora by in vitro experiments. Crude saccharides (CS) were prepared by 50 g dried potato pulp suspended in 1 L of pure water. The suspensions were autoclaved at 1211C for 2 h, and filtered by a filter paper. The filtrate were concentrated around 1/4 by a rotary evaporator, and aggregated by 4× volume of ethanol. Dialyzed saccharides (DS) were prepared to dialyzed CS by a dialysis membrane (cut off MW < 10,000). Enzyme-treated saccharides (ES) were prepared to digest CS by a crude amylase, Gruku-Gin (Amano Enzyme) and dialyzed. All saccharides were lyophilized or heat-dried to store. According to size-exclusion chromatography, the molecular distribution of CS were between 400 and 200,000. A peak of oligosaccharides was observed around MW 800. The peak were disappeared in charts of DS and ES. Glucan were occupied 50% in the total amount of glycan in CS and DS, and decreased to approx. 5% in ES. When thirteen strains of gut microbes were cultivated in GAM broth including the saccharides instead of glucose, CP and EP selectively stimulated several non-pathogenic Bifidobacterium and Clostridium, but not pathogenic Enterobacteriaceae.

Effect of Potato Pulp Pectic Polysaccharide on the Stability of Acidified Milk Drinks

In order to broaden the application of potato pulp pectic polysaccharide (PPP) in stabilizing acidified milk drinks (AMDs) and investigate the stabilizing effect and physical properties of AMDs prepared with PPP, a comparative study was made among PPP, commercial high methoxyl pectin (HMP) and low methoxyl pectin (LMP). The zeta potential, rheology, particle size and serum separation of AMDs were evaluated after preparing with PPP, HMP and LMP, respectively. Results indicated that PPP led to lower serum separation than LMP (14.65% for AMDs prepared with 0.5% PPP compared to 25.05% for AMDs prepared with 0.5% LMP), but still higher than HMP (9.09% for AMDs prepared with 0.5% HMP). However, narrower particle size distribution and lower viscosity of AMDs was achieved by PPP than by LMP and HMP. PPP can electrostatically adsorb on the surface of casein and its abundant neutral sugar side chains would provide steric hindrance to prevent casein flocculation in AMDs. Our results might provide some new ideas for the application of PPP in improving the stability of AMDs.

Effect of addition of dried potato pulp on selected quality characteristics of shortcrust pastry cookies

Potato pulp is a nuisance waste from the production of potato starch, containing large amounts of dietary fiber; therefore, addition of the pulp to food may have a positive effect on the nutritional value of food products. To increase the amount of dietary fiber, shortcrust pastry cookies were baked by replacing some of the flour (20–100%) with an equivalent amount of dried potato pulp. In all the tested variants, correct confectionery products were obtained. The color of finished product (measured using Konica-Minolta CM-5 spectrophotometer) and mechanical properties of raw dough and baked cookies (subjected to a tensile test, using INSTRON 5544 Tensile Tester) were determined. Furthermore, the samples were subjected to sensory consumer assessment (evaluated on a 7-point hedonic scale). Colorimetric tests of the cookies showed a slight shift in their color from yellow toward green but at the same time lowering its saturation. Strength tests show that only the replacement of more than 40% of flour by the dried pulp resulted in a significant increase in the hardness of baked products. Regarding the tests with consumers, cookies containing up to 40% potato pulp were acceptable. Such a large addition of potato pulp to shortcrust pastry cookies creates new opportunities for this waste management.