Total dietary fiber content

Total dietary fiber (TDF) content of potato dry matter is determined according to the AACC (2000) method 32-05 following the total dietary fiber assay procedure (Megazyme k-TDFR 01/05). This is a gravimetric method that is simpler and faster than other analysis methods. In addition to total dietary fiber content, both soluble and insoluble dietary fiber content can be determined by this method. 

Animal feeds as well as human diets vary considerably in the type and quantity of dietary fiber. Wise and Gilbert (9) using modified detergent methods analyzed fourteen commercial rodent diets and found that the total dietary fiber content varied from 8.3 to 22.4%. In fact, it is not unusual for commercially available cereal-based rodent diets to contain 20% dietary fiber on a dry weight basis (10). In general, the fermentable fibers constitute more than half of the total dietary fiber the remainder composed of the fibers more resistant to fermentation, such as cellulose and lignin (9). Thus, a significant portion of rodent diets has the potential to be fermented in the intestinal tract. 

In vitro digestibility (a-amylase) of raw quinoa starch was reported at 22%, while that of autoclaved, cooked, and drum-dried samples was 32%, 45%, and 73%, respectively (Ruales and Nair, 1994a). Saponins did not affect the digestibility of the starch. The total dietary fiber content in quinoa flour is affected by thermal treatment, while the insoluble dietary fiber fraction does not change with heat treatment (Ruales and Nair, 1994b). 

Ramalu P and Rao PU. 2003. Total, insoluble and soluble dietary fiber contents of Indian fruits. J Food Compos Anal 16 677-685. 

Wehmeyer et al. (1969), Bower et al. (1988), and Amarteifio and Moholo (1998) reported the content of carbohydrate to be 23%, 24%, and 19%, respectively. These values have been obtained indirectly as the difference between 100% and the content of proteins, lipids, and minerals. Holse et al. (2010) found that the content of carbohydrate was dominated by total dietary fiber as it varied between 18.7% and 26.8% dm (Table 5.2). The majority of the dietary fiber is insoluble as only about 4% of the dietary fibers are soluble. Comparing the content of total dietary fiber of morama bean with the content of peanut (9% dm) and soybean (10% dm) (U.S. Department of Agriculture, 2007), it appears that the morama bean has a considerably higher level of indigestible carbohydrates. Holse et al. (2010) also reported a very low starch content, which is in contrast to other legumes, in which starch is usually the most abundant carbohydrate... 

The bulk of potato tubers is made up of parenchyma cells that have thin, non-lignified, primary cell walls (Reeve et al., 1971 Bush et al, 1999, 2001 Parker et al., 2001). Unless stated to the contrary, potato cell walls refers to parenchyma cell walls. These walls and their component polysaccharides are important for a number of reasons they form part of the total intake of dietary fiber, influence the texture of cooked potato tubers and form much of the waste pulp that is produced in large amounts by the potato starch industry when starch is isolated. The pulp is usually used as cattle feed, but potentially could be processed in a variety of ways to increase its value (Mayer, 1998). For example, the whole cell-wall residues could be used as afood ingredient to alter food texture and to increase its dietary-fiber content, or cell-wall polysaccharides could be extracted and used in a similar way or for various industrial applications (Turquois et al., 1999 Dufresne et al, 2000 Harris and Smith, 2006 Kaack et al., 2006). 

Diets are isocaloric. The composition of the test and control (reference protein) diet (calculated on a dry weight basis) is 10% protein (1.6% nitrogen), 1 % AIN vitamin mix 76,3.5% AIN mineral mixture 76 (Nutritional Biochemicals), 0.2% choline bitartrate, 5% cellulose (only if test food is <5% total dietary fiber), corn oil to 10% total fat, and corn starch to total 100%. To account for differences in the protein content of the test diet, the level of corn starch can be adjusted (Joint FAO/WHO Expert Consultation, 1991). The chemical composition (proximate analysis) of the test protein must be measured before test diets are formulated. The proximate analysis of the test and control diets are to be measured after the diets are formulated, but before they are fed, to ensure that the protein content is the same for all diets, and that the diets are isocaloric. 

At the present time, only five peer-reviewed research articles exist, which provide compositional information on the carbohydrates present in the pecan [23,27,28,30,43]. Four of the research studies [23,27,30,43] only deal with sugars, whereas research by Wakeling et al. [28] offers data on sucrose content and total dietary fiber. It is highly evident that a systematic study to define the carbohydrate composition of pecan does not exist to allow in-depth discussions and comparisons to other nuts or foods. Therefore, the following sections only review the available research reports and point out discrepancies in the data where they exist. 

The composition of avocado, in tenns of macronutrients, has been widely studied and is compiled in different tables of food composition. According to the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference [83], 100 g of avocado are an important source of energy (160 kcal) and contain 73.23 g of water, 2 g of proteins, 14.66 g of total fat (67% monounsaturated, 12% polyunsaturated, and 14% saturated fatty acids), and 8.53 g of carbohydrates, of which 6.70 g are total dietary fiber and 0.66 g are sugars. As it can be seen, one of the main components of avocado is the fat, and thus it is not surprising that it is also known as butter fruit. Besides, some of the principal health benefits of avocado have been attributed to its high monounsaturated fatty acid content. These facts make lipids one of the most studied families of compounds in avocado. 

The composition of cereal food products can be signiflcantly modified by additives and some processing methods. For example, psyllium is often added to cereal products to increase the soluble fiber content however, the accepted method for measuring total dietary fiber (AOAC Method 991.43, Ref. 1) is not accurate for psyllium-containing products and must be modified by the addition of a sonification step (33). Similarly, some low- or no-calorie sugar and fat substitutes and their carriers, used in certain... 

W. R. Windham, S. E. Kays, F. E. Barton, n. Effect of cereal product residual moisture content on total dietary fiber determined by near-infrared reflectance spectroscopy, J. Agric. Food Chem. 45 140-144, 1997. 

Saturated fatty acids as a group affect factors involved in cholesterol metabolism. Relative to the carbohydrate content of the diet, a decrease in saturated fat content induces a favorable decrease in serum total and LDL cholesterol concentrations but unfavorably reduces HDL cholesterol concentrations. Both increasing and decreasing effects of saturates on platelet aggregation have been observed, as well as the absence of effect, so results are inconsistent and difficult to interpret. Whether the beneficial effect of a diet low in saturated fat on the prethrombotic state of blood depends on the dietary fiber content is still unclear. 

Analytical Methods. The samples were analyzed by standard AACC (21) procedures for moisture (air-oven method), protein (Method 46-13), crude fat (Method 30-25), crude fiber (Method 32-10), insoluble dietary fiber (Method 32-20) and ash (600°C, 3 hr). Starch content was determined by the polarimeter method (Method 76-20) and total sugars by Method 80-60. Color characteristics of the dried products were evaluated with the Hunter Color Difference Meter. 

Closely related to its superfruit cousins, the blackberry and black raspberry, red raspberry is a Rubus member of the rose family, Rosaceae. This group of fruits is characterized by its many individual drupelets, each like a small berry with one seed. The dozens of individual drupelets in one Rubus berry contribute extra skin, seeds, and pectin, which result in high dietary fiber and micronutrient value. This design places the red raspberry among the highest fiber-content plant foods known. The red raspberry is approximately 20 percent fiber by total weight ... 

Cauliflower has a very high waste index (Kulkami et ah, 2001) and is an excellent source of protein (16.1%), cellulose (16%), and hemicellulose (8%) (Wadhwa et ah, 2006). It is considered as a rich source of dietary fiber and it possess both antioxidant and anticarcinogenic properties. Phenolic compounds and vitamin C are the major antioxidants of brassica vegetables, due to their high content and high antioxidant activity (Podsedek, 2007). Lipid-soluble antioxidants (carotenoids and vitamin E) are responsible for up to 20% of the brassica total antioxidant activity. The level of nonstarch polysaccharide (NPS) in the upper cauliflower stem is similar to that of the floret and both are rich in pectic polysaccharides, while the cauliflower lower stem is rich in NPS due mainly to cellulose and xylan deposition (Femenia et ah, 1998). 

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