Potato is the world's most important vegetable crop, with nearly 400 million tons produced worldwide every year, lending to stability in food supply and socioeconomic impact. In general, potato is an intensively managed crop, requiring irrigation, fertilization, and frequent pesticide applications in order to obtain the highest yields possible. Important traits are easy to find in wild relatives of potato, but their introduction using traditional breeding can take 15-20 years. This is due to sexual incompatibility between some wild and cultivated species, a desire to remove undesirable wild species traits from adapted germplasm, and difficulty in identifying broadly applicable molecular markers. Fortunately, potato is amenable to propagation via tissue culture and it is relatively easy to introduce new traits using currently available biotech transformation techniques. For these reasons, potato is arguably the crop that can benefit most by modern biotechnology. The benefits of biotech potato, such as limited gene flow to conventionally grown crops and weedy relatives, the opportunity for significant productivity and nutritional quality gains, and reductions in production cost and environmental impact, have the potential to influence the marketability of newly developed varieties. In this review we will discuss current and past efforts to develop biotech potato varieties, traits that could be impacted, and the potential effects that biotech potato could have on the industry.Resumen La papa es el cultivo hortícola más importante en el mundo, con cerca de 400 millones de toneladas producidas a nivel mundial anualmente, acreditando la estabilidad en el suministro de alimentos e impacto socioeconómico. En general, la papa es un cultivo manejado intensivamente, que requiere riego, fertilización y aplicaciones frecuentes de plaguicidas para obtener los más altos rendimientos posibles. Los caracteres importantes son fáciles de encontrar en parientes silvestres de la papa, pero su introducción usando el mejoramiento tradicional puede llevar de 15 a 20 años. Esto es debido a la incompatibilidad sexual entre algunas especies silvestres y cultivadas, el deseo para eliminar características indeseables de las especies silvestres del germoplasma adaptado, y la dificultad en la identificación de marcadores moleculares aplicables ampliamente. Afortunadamente, la papa es receptiva a la propagación por cultivo de tejidos y es relativamente fácil la introducción de nuevos caracteres usando técnicas biotecnológicas de transformación actualmente disponibles. Por estas razones, la papa es probablemente el cultivo que se puede beneficiar mayormente por la biotecnología moderna. Los beneficios de la papa biotecnológica, como el flujo genético limitado a cultivos que se siembran convencionalmente y a los parientes como malezas, la oportunidad para productividad significativa y logros en calidad nutricional, y las reducciones en los costos de producción e impacto ambiental, tienen el potencial para influenciar la comercialización...

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Bioavailabilities of heme iron prepared from lyophilized, fresh, cooked, nitrosylated hemoglobin and purified myoglobin in semipurified diets were investigated in two experiments. In experiment 1, the bioavailabilities of porcine and bovine hemoglobins were about one-third that for ferrous sulfate regardless of hemoglobin treatments. The efficiency of hemoglobin regeneration by anemic rats fed nitrosylated pork hemoglobin was significantly depressed compared with that by those fed unnitrosylated products. Cooking did not affect the availability of the heme iron, whereas washing tended to increase it. In experiment 2, the hemoglobin regeneration efficiency of the purified myoglobin diet was lower than reported by others for meat diets, and was even lower than that of the purified hemoglobin diet. The respective efficiency values for the basal, basal + FeSO4, hemoglobin, and myoglobin diets (experiment 2) were 0.073, 0.581, 0.199, and 0.125. The efficiencies of converting hemoglobin and ferrous sulfate iron into hemoglobin by the anemic rats were very similar to reported absorption values for these iron sources by iron-deficient human subjects.

Acrylamide forms primarily from a reaction between reducing sugars (e.g., glucose and fructose) and an amino acid (asparagine, Asn) formed naturally in foods, including potatoes. This reaction occurs when carbohydrate-rich foods are heated at temperatures above 120 °C. Multiple potato varieties were transformed with potato genomic DNA that results in down-regulation of the expression of the asparagine synthetase-1 gene (Asn1), significantly reducing synthesis of free Asn, and consequently lowering the potential to form acrylamide during cooking. These potatoes with low acrylamide potential (LAP) were tested in agronomic trials, and processed into French fries and potato chips. Decreased levels of acrylamide were measured in these cooked food products when derived from LAP potatoes compared with those derived from conventional potatoes. These reductions can be directly attributed to reduction in Asn levels in the LAP potatoes. The corresponding average reduction in exposure to acrylamide from French fry and potato chip consumption is estimated to be 65%, which would amount to approximately a 25% reduction in overall dietary exposure. Considering that children consume nearly three times more acrylamide than adults on a per kg body weight basis, they would experience the most impact from the reduced acrylamide associated with LAP potatoes. The potential public health impacts, in context of dietary acrylamide exposure reduction, are discussed in this study.

Iron binding systems (heme iron binding gases alone or with iron binding salts) were evaluated for antibotulinal activity in ground pork. Compared with meat systems containing nitrite or nitrite plus supplemental iron compounds, carbon monoxide (CO) was not antibotulinal. Nitric oxide (NO) treated meats did swell slower, but nitrite was also found in these systems. Thus, neither CO nor NO would be suitable substitutes for sodium nitrite in meat curing. Addition of ferric chloride or myoglobin decreased the antibotulinal effectiveness of nitrite, but samples containing nitrite plus ethylenediaminetetraacetate (EDTA) or denatured nitrosylated myoglobin (NOMb) swelled slower. Supplemental iron compounds probably decreased residual nitrite levels in the product, thus permitting botulinal growth, rather than directly stimulating growth by providing iron as an external nutrient.

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A number of methods for determining dietary fiber have been suggested. Thus, ten modifications of the neutral detergent fiber (NDF) procedure were compared using spinach, bread, and parsnips. Use of Bacillus subtilis alpha amylase resulted in lower (p < .01) NDF values than did porcine pancreatic amylase. Amylase obtained from B. subtilis may contain other enzymes such as hemicellulase and cellulase in small amounts. These enzymes would be undesirable since they may remove some of the fiber fraction, hence the reported NDF would be lower. Temperature of incubation, 21°C or 37°C, did not significantly affect fiber values. Samples predigested with amylase had higher (p < .01) fiber values in a high starch food than samples in which amylase incubation occurred after detergent digestion. NDF values may have been higher because starch was less available for enzymatic hydrolysis before the detergent digestion. When amylase was added directly to the detergent solution after refluxing, NDF was not significantly different (p < .05) from that quantified by the official AACC method or most of the other treatments. Implications of these findings are discussed with respect to their significance in practical applications.

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