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PubMed2003

Productivity improvements in rice.

Rice comprises 23%--an immense proportion-of the calories consumed worldwide. Countries that rely on rice as the main staple often consume up to 60% of their daily calories from this cereal product. During the Green Revolution, the yield potential of rice was greatly improved, which is especially important owing to the rapidly growing population. This article reviews the potential contributions of biotechnology to further rice yield potential.

Developing Countries↗
PubMed2001

Transgenic foods, pesticides, dioxin, passive smoke. Consequences on breast milk.

In recent years the efforts of companies manufacturing cow milk (CM) formulas have led to the development and availability of special formulas, which have dramatically reduced the morbidity of infants with food allergy (FA). However, the safety of several infants and children with food allergy is put to a severe test by transgenic foods, pesticides, and dioxin entering the scenario, also provoking breast milk contamination. Regarding transgenic foods, it is significant the attitude taken against people attempting to call them Frankenstein food, whereas pesticides and dioxin present in dietary foods for infants and young children, after a first arising of alarmed and inflamed controversies, have almost fallen into oblivion. Several of these substances are able to trigger immune alterations. Recent reports have shown that pears can contain pesticides in 54% of cases, a finding which obliges us to review elimination diets devised for allergic babies. However, these foods are far from being ideal both from the nutritional adequacy and hypoallergenicity; moreover, passive smoke is now a genetic factor. We would like to stress, according to the Latin wisdom that stands on the portal of our Clinic in puero homo, which means. In infant is the seed of the future man, that our goal is not only to reduce morbidity and mortality, but mainly to insure the best quality of life both to infants and adults.

Dioxins↗
PubMedDate not supplied

[Genetic influence on energy requirements. III. Multifactorial inheritance modified by gender].

A conversion index (CI) which measures the efficiency of utilization of dietary energy was found to be normally distributed in Wistar rats. The CI used was a ratio of the amount of food ingested to achieve an increment of one gram of body weight during the period of 32 days starting on day 21 after weaning. We have previously reported that male rats are more efficient energy converters than females. As a way to explore the hypothesis that the inheritance of the regulation of energy requirements is multifactorial, we mated F1 rats with high CI (poor energy converters) and studied the CI of their F2 offspring. The males behaved in agreement with the hypothesis as the F2 males had higher CI than the F1 males, but the behavior in females was different, i.e. the F2 were better converters than the F1. We have no explanation for this gender discrepancy.

Animals↗
PubMed2003

Genetic and environmental aspect of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a heterogeneous syndrome determined in most patients by the association of two main factors: hyperandrogenism and insulin resistance. These characters are probably independent of each other and seem to be inherited by several different mechanisms. In some patients homozygous gene alteration has been found but in most patients PCOS seems to be determined by the association of gene polymorphisms that are common in the general population but alone are unable to determine phenotypic consequences. Alteration of genes that regulate the initial steps of ovarian steroidogenesis is probably the main causal factor of hyperandrogenism. Insulin resistance may be the result of many different gene alterations including insulin receptor substrate (IRS)-1 and 2, calpain-10 and peroxisome proliferator-activated receptor gamma(PPARgamma). Some polymorphisms may be protective against other gene alterations. Insulin sensitivity is also modified by socioeconomic and cultural factors that influence quantity and quality of food and energy expenditure. However, even eating behavior and weight response to food intake may be under genetic regulation. Different combinations of multiple gene polymorphisms and of environmental factors explain the heterogeneity of PCOS.

Eating↗
PubMed2002

Controversial medical and agri-food biotechnology: a cultivation analysis.

Whether biotechnology is one or several developments is not clear. Once distinctions are required, the question is: Which one prevails? When the good, the bad, and the ugly settle, where do they fall? Evaluation implies distinction, and representation drives attitude. The controversies over biotechnology are fertile ground on which to study these issues. The imports of genetically modified (GM) soya into Europe in 1996-97 and the cloning of Dolly the sheep from adult cells in 1997 changed the symbolic environment for genetic engineering. The ensuing public controversies came to focus mainly on field trials of GM crops and food labeling. This paper will explore the relationship between quality press coverage and public perception, in particular the cultivation of the contrast between "desirable" biomedical (RED) and "undesirable" agri-food (GREEN) biotechnology in Britain. The argument draws on a systematic analysis of the British press coverage of biotechnology from 1973 to 1999 and analysis of public perceptions in 1996 and 1999. The paper concludes that the debate over GM crops and food ingredients fostered the RED-GREEN contrast among the newspaper-reading public, thereby shielding RED biotechnology from public controversy, and ushered in a realignment of the regulatory framework in 2000.

Biotechnology↗
PubMed2005

Consumer preferences for food product quality attributes from Swedish agriculture.

This paper employs a choice experiment to obtain consumer preferences and willingness to pay for food product quality attributes currently not available in Sweden. Data were obtained from a large mail survey and estimated with a random parameter logit model. We found evidence for intraproduct differences in consumer preferences for identical attributes, as well as interproduct discrepancies in ranking of attributes. Furthermore, we found evidence of a market failure relating to the potential use of genetically modified animal fodder. Finally, we found support for the idea that a cheap-talk script can alleviate problems of external validity of choice experiments. Our results are useful in forming product differentiation strategies within the food industry, as well as for the formation of food policy.

Agriculture↗
PubMed2006

Gene transfer and cauliflower mosaic virus promoter 35S activity in mammalian cells.

The cauliflower mosaic virus 35S promoter (CaMV35s) is extensively used in genetically modified crops for human and animal consumption. Horizontal gene transfer is attracting particular attention, in light of experimental reports, showing the presence of dietary DNA into animal tissues. Health implications may derive from possible activities of the heterologous promoter in mammalian cells after integration in the host genome. To evaluate this hypothesis, in vivo and in vitro experiments were performed using GFP as reporter gene. Recombinant plasmid DNA was fed to Balb/c mice and searched in several tissues by PCR amplification. The activity of the plant virus promoter was assessed by RT-PCR and fluorescence microscopy after liposome-mediated transfection of murine gonadic cells. Obtained data did not highlight evidences of dietary DNA transfer in mice. No CaMV35s transcriptional activity was detected in this experimental model. These findings emphasize the need for further studies and standardized methods.

Animals↗
PubMed2003

Flavor preferences conditioned in C57BL/6 mice by intragastric carbohydrate self-infusion.

This study determined the feasibility of conditioning flavor preferences in mice by self-administered intragastric (IG) nutrient infusions. Male C57BL/6J mice were surgically fitted with an IG catheter that was attached by a tether system to an infusion pump. The mice were given ad-libitum access to chow and a flavored solution 23 h/day. Drinking was monitored with a computerized lickometer system that controlled the infusion pumps. In Experiment 1, drinking one flavored solution (CS+, e.g., grape-saccharin) was paired with matched infusions of 8% maltodextrin, whereas drinking another solution (CS-, e.g., cherry-saccharin) was matched with water infusions across 6 one-bottle training days. During training, the mice drank more CS+ than CS-; this was due to an increase in bout size but not bout frequency. In subsequent two-bottle choice tests, the mice strongly preferred (91%) the CS+ to the CS-. Experiment 2 obtained a significant but less robust (71%) CS+ preference in mice trained with unsweetened CS solutions. These data indicate that mice, like rats, acquire an increased acceptance and preference for flavors paired with the postingestive actions of nutrients. Our understanding of flavor-nutrient learning can be advanced by studying this process in selected mouse strains and genetically modified animals.

Animals↗
PubMed2026

Genomic determinants underlying biogenic amine detoxification phenotypes in food-associated lactic acid bacteria: Mechanism, evolutionary origin, and relevance to fermented food safety.

Biogenic amines (BAs) are toxic metabolites that accumulate in fermented foods and pose significant food safety concerns. Although several lactic acid bacteria (LAB) have previously been reported to exhibit strain-specific BA-degrading phenotypes, the genetic determinants underlying these activities have remained largely uncharacterized. Here, we analyzed 8251 LAB genomes to validate BA-degrading phenotypes. We predicted five BA-associated genes, including two direct biogenic amine-degrading genes (BADGs), mco and patA, and three polyamine-modifying genes (PMGs), speG, paiA, and bltD. Among BADGs, mco was broadly distributed across LAB and strongly enriched across food-associated niches. patA, organized within a conserved potD-glnB-potABC-patA cassette, is a putative, functionally distinct BADG in LAB, revealing a nitrogen-responsive polyamine uptake-catabolism module. Phylogenomics, phylogenetic reconciliation, and synteny analysis established that all five genes entered the LAB through episodic horizontal gene transfer followed by lineage-specific fixation. GC compositional bias and mobile genetic element association further corroborated the horizontal origin of the two BADGs. Structural analysis confirmed the conservation of catalytic core residues of BADGs across LAB, indicating strong purifying selection. Phenotype-to-genotype correlation with experimentally reported LAB suggested mco as a reliable genomic predictor of degrading phenotype. Integration of degradation and biosynthetic profiles predicted multiple LAB species capable of both synthesizing and degrading BA, along with 1823 genomes with degradation potential but lacking detectable BA biosynthesis genes. This study provides the first large-scale genome framework linking BA-degrading phenotypes with their genetic determinants in LAB and offers a rational basis for selecting BA-detoxifying strains for fermented food applications.

Biogenic Amines↗
PubMed2006

Metabolism of [14C]-2,4-dichlorophenol in edible plants.

Several 2,4-dichlorophenoxyacetic acid (2,4-D)-sensitive plants have been modified by genetic engineering with tfdA gene to acquire 2,4-D tolerance. The expression product of this gene degrades 2,4-D to 2,4-dichlorophenol (DCP), which is less phytotoxic but could cause a problem of food safety. After a comparison of 2,4-D and DCP metabolism in transgenic 2,4-D-tolerant and wild cotton (Gossypium hirsutum L.), a direct study of DCP metabolism in edible plants was performed. After petiolar uptake of a [U-phenyl-(14)C]-DCP solution followed by a 48 h water chase, aqueous extracts were analysed by high-performance liquid chromatography. Metabolites were thereafter isolated and their structural identities were determined by enzymatic and chemical hydrolyses and mass spectrometry analyses. The metabolic fate of DCP was equivalent to 2,4-D metabolism in transgenic 2,4-D-tolerant cotton. In addition, DCP metabolism was similar in transgenic and wild cotton. The major terminal metabolites were DCP-saccharide conjugates in all species, essentially DCP-(6-O-malonyl)-glucoside or its precursor DCP-glucose. The significance of this metabolic pathway with regard to food safety is discussed.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2002

Expression of human milk proteins in plants.

Human milk proteins are believed to have a multitude of biological activities benefiting the newborn infant. Such functions include antibacterial and antiviral activities, enhancement of the immune system and increased nutrient absorption. To date, only breast-fed infants have been exposed to these proteins. However, by using genetic engineering it is now possible to express these proteins in plants, such as rice, at very high levels. Recombinant human milk proteins can subsequently be added to infant formula and baby foods. Prior to such addition, safety tests and efficacy trials need to be conducted. The safety tests will initially be done in rats and then in humans. The efficacy trials should also evaluate stability against heat treatment (processing), pH (stomach conditions) and proteolytic enzymes (digestion). To date, we have expressed recombinant human lactoferrin, lysozyme and alpha1-antitrypsin in rice at very high expression levels. These recombinant proteins showed a stability and activities similar to those of the native milk proteins, suggesting that they may be able to exert biological activities in infants when added to formula or baby foods.

Humans↗
PubMed2002

Genetic engineering of a zeaxanthin-rich potato by antisense inactivation and co-suppression of carotenoid epoxidation.

Zeaxanthin is an important dietary carotenoid but its abundance in our food is low. In order to provide a better supply of zeaxanthin in a staple crop, two different potato (Solanum tuberosum L.) varieties were genetically modified. By transformation with sense and antisense constructs encoding zeaxanthin epoxidase, zeaxanthin conversion to violaxanthin was inhibited. Both approaches (antisense and co-suppression) yielded potato tubers with higher levels of zeaxanthin. Depending on the transgenic lines and tuber development, zeaxanthin content was elevated 4 to 130-fold reaching values up to 40 microg/g dry weight. As a consequence of the genetic manipulation, the amount of violaxanthin was diminished dramatically and in some cases the monoepoxy intermediate antheraxanthin accumulated. Between one and eight copies of the sense or antisense epoxidase gene fragments were integrated into the genome. In addition, most of the transformants with higher zeaxanthin levels showed also increased total carotenoid contents (up to 5.7-fold) and some of them exhibited reduced amounts of lutein. The increase in total carotenoids suggests that the genetic modification affects the regulation of the whole carotenoid biosynthetic pathway in potato tubers. Northern blot analysis demonstrated that upregulation of carotenogenesis in the transgenics is accompanied by substantial higher phytoene synthase transcript levels in 6-week-old tubers and a very slight increase of the beta-carotene hydroxylase transcript. The amount of the deoxyxylulose 5-phosphate synthase mRNA was very similar in wild type and transformed tubers. Abscisic acid content of tubers remained unchanged whereas alpha-tocopherol was 2 to 3 fold elevated in the transformants.

Carotenoids↗
PubMed1996

Soluble acid invertase determines the hexose-to-sucrose ratio in cold-stored potato tubers.

Cold storage of potato (Solanum tuberosum L.) tubers is known to cause accumulation of reducing sugars. Hexose accumulation has been shown to be cultivar-dependent and proposed to be the result of sucrose hydrolysis via invertase. To study whether hexose accumulation is indeed related to the amount of invertase activities, two different approaches were used: (i) neutral and acidic invertase activities as well as soluble sugars were measured in cold-stored tubers of 24 potato cultivars differing in the cold-induced accumulation of reducing sugars and (ii) antisense potato plants with reduced soluble acid invertase activities were created and the soluble sugar accumulation in cold-stored tubers was studied. The cold-induced hexose accumulation in tubers from the different potato cultivars varied strongly (up to eightfold). Large differences were also detected with respect to soluble acid (50-fold) and neutral (5-fold) invertase activities among the different cultivars. Although there was almost no correlation between the total amount of invertase activity and the accumulation of reducing sugars there was a striking correlation between the hexose/sucrose ratio and the extractable soluble invertase activity. To exclude the possibility that other cultivar-specific features could account for the obtained results, the antisense approach was used to decrease the amount of soluble acid invertase activity in a uniform genetic background. To this end the cDNA of a cold-inducible soluble acid invertase (EMBL nucleic-acid database accession no. X70368) was cloned from the cultivar Desirée, and transgenic potato plants were created expressing this cDNA in the antisense orientation under control of the constitutive 35S cauliflower mosaic virus promotor. Analysis of the harvested and cold-stored tubers showed that inhibition of the soluble acid invertase activity leads to a decreased hexose and an increased sucrose content compared with controls. As was already found for the different potato cultivars the hexose/sucrose ratio decreased with decreasing invertase activities but the total amount of soluble sugars did not significantly change. From these data we conclude that invertases do not control the total amount of soluble sugars in cold-stored potato tubers but are involved in the regulation of the ratio of hexose to sucrose.

Cold Temperature↗
PubMed2004

Nixtamalized flour from quality protein maize (Zea mays L). optimization of alkaline processing.

Quality of maize proteins is poor, they are deficient in the essential amino acids lysine and tryptophan. Recently, in Mexico were successfully developed nutritionally improved 26 new hybrids and cultivars called quality protein maize (QPM) which contain greater amounts of lysine and tryptophan. Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa, tortillas, flours, snacks). Processors adjust nixtamalization variables based on experience. The objective of this work was to determine the best combination of nixtamalization process variables for producing nixtamalized maize flour (NMF) from QPM V-537 variety. Nixtamalization conditions were selected from factorial combinations of process variables: nixtamalization time (NT, 20-85 min), lime concentration (LC, 3.3-6.7 g Ca(OH)2/l, in distilled water), and steep time (ST, 8-16 hours). Nixtamalization temperature and ratio of grain to cooking medium were 85 degrees C and 1:3 (w/v), respectively. At the end of each cooking treatment the steeping started for the required time. Steeping was finished by draining the cooking liquor (nejayote). Nixtamal (alkaline-cooked maize kernels) was washed with running tap water. Wet nixtamal was dried (24 hours, 55 degrees C) and milled to pass through 80-US mesh screen to obtain NMF. Response surface methodology (RSM) was applied as optimization technique, over four response variables: In vitro protein digestibility (PD), total color difference (deltaE), water absorption index (WAI), and pH. Predictive models for response variables were developed as a function of process variables. Conventional graphical method was applied to obtain maximum PD, WAI and minimum deltaE, pH. Contour plots of each of the response variables were utilized applying superposition surface methodology, to obtain three contour plots for observation and selection of best combination of NT (31 min), LC (5.4 g Ca(OH)2/l), and ST (8.1 hours) for producing optimized NMF from QPM.

Calcium Compounds↗