Nutrients, loss

If food can be heated quickly to a temperature of I3I°C a lethaUty equivalent to 6 min at I2I°C can be accumulated in 36 s. This rapid heating and cooling of hquid foods, such as milk, can be performed in a heat exchanger and is known as high temperature—short time (HTST) processing. HTST processing can yield heat-preserved foods of superior quahty because heat-induced flavor, color, and nutrient losses are minimized. 

Biomass Redistribution Associated with Deforestation and Fire. The influence of deforestation on biogeochemical cycles is dependent upon a number of factors associated with the unique characteristics of the ecosystem (climate, soils, topography, etc), the quantity of the total nutrient pool stored in aboveground biomass (Table II), and the level of disturbance (i.e. the degree of canopy removal, soil disturbance, and the quantity of wood or other forest products exported from the site). The quantity of biomass consumed by one or more slash fires following deforestation can also dramatically increase nutrient losses, influence post fire plant succession, and hence, postfire biogeochemical cycles. 

Nutrient Losses Associated With Biomass Burning. Nutrient losses associated with slash fires occur through volatilization and convective losses of ash. Elements with low temperatures of volatilization (e.g. N, K, S, and some organic forms of P) will be lost in the highest quantities (Table III) (57). Conversely, Ca and Mg have volatilization temperatures higher than that recorded during most vegetation fires. Almost all fire-induced losses of these elements are due to particulate transfer by convective processes. 

Table IV. Biomass and nutrient losses associated with wood harvest (fuel wood or timber export) and fire in selected forest ecosystems.

Much of the surface soil erosion and hence nutrient loss occurs when deforestation and biomass burning removes and/or consumes the organic materials that protect the soil surface. Significant losses may occur by dry ravel or overland water erosion associated with precipitation events. Under a shifting cultivation system in a tropical deciduous forest ecosystem in Mexico, Maass et al. 61) reported first year losses of N, P, K, and Ca were 187, 27, 31, and 378 kg ha" respectively. In contrast, losses in adjacent undisturbed forests were less than 0.1 kg ha for all nutrients except Ca (losses were 0.1-0.5 kg ha for Ca). 

Figure 7. Another temperate coniferous forest site of the Pacific Northwest, USA following clearcutting and slash burning. Severe levels of deforestation result in large quantities of nutrient losses through wood export, biomass burning and accelerated erosion and leaching losses. (Photograph is by courtesy of Dian L. Cummings. ...

Reduction in dietary protein intake has been shown to slow the progression of kidney disease.8 However, protein restriction must be balanced with the risk of malnutrition in patients with CKD. Patients with a GFR less than 25 mL/minute/ 1.73 m2 received the most benefit from protein restriction 8 therefore, patients with a GFR above this level should not restrict protein intake. The NKF recommends that patients who have a GFR less than 25 mL/minute/1.73 m2 who are not receiving dialysis, however, should restrict protein intake to 0.6 g/kg per day. If patients are not able to maintain adequate dietary energy intake, protein intake maybe increased up to 0.75 g/kg per day.15 Malnutrition is common in patients with ESRD for various reasons, including decreased appetite, hypercatabolism, and nutrient losses through dialysis. For this reason, patients receiving dialysis should maintain protein intake of 1.2 g/kg per day to 1.3 g/kg per day. 

The values quoted above are for FYM from overwintered cattle, but the method of housing influences nutrient loss. With cattle in covered yards sufficient bedding must be used to absorb the liquid manure and there is little or no drainage the dung is kept well compressed by the animals and fermentation is reduced to a minimum. Under such conditions very little loss takes place. 

In addition to a complete water balance, EPIC estimates plant biomass production, fertilizer use, wind and water erosion, loss of nitrogen and phosphorus from the soil, and the effect of nutrient loss from the soil on plant growth. 

Quintem, N. (2005). Integration of organic pig production within crop rotation Implications on nutrient losses . Landbauforschung Volkenrode, Special Issue, 281, 31-40. 

Heard J, Cavers C, Adrian G (2006) Up in smoke-nutrient loss with straw burning. Better Crops 90 10-11... 

An adequate and balanced supply of nutrients in the soil is essential for several reasons. Nutrient surpluses might result in nutrient losses which subsequently could lead to water and air contamination (see chapter 3.2.2 and 3.2.3) and eutrophication. However, nutrient deficiency is synonymous with the overexploitation of soil nutrients in the long run and leads to a decrease in yield and product quality. 

At low and medium doses, it is well established that the nutritional value of proteins, carbohydrates, and fats as macronutrients are not significantly impaired by irradiation, and neither the mineral bioavailability is impacted. Like all other energy depositing process, the application of ionizing radiation treatment can reduce the levels of certain sensitive vitamins. Nutrient loss can be minimized by irradiating food in a cold or frozen state and under reduced levels of oxygen. Thiamin and ascorbic acid are the most radiation sensitive, water-soluble vitamins, whereas the most sensitive, fat-soluble vitamin is vitamin E. In chilled pork cuts at the 3 kGy maximum at 0-10°C, one may expect about 35 0% loss of thiamin in frozen, uncooked pork meat irradiated at a 7 kGy maximum at —20°C approx., 35 % loss of it can be expected [122]. 

Senyk, G. F. and Shipe, W. F. 1981. Protecting your milk from nutrient losses. Dairy Field 164, 81-85. 

Studies of the MA-lysine reaction by other authors, as discussed previously, were conducted at 37°C or lower. There are a few reports of lysine losses measured as a function of increasing temperature to more than 100°C some of these reports correlate these losses with browning and others with moisture content (21-26). However, most studies of high temperature effects have been on browning rather than nutrient loss. 

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