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The floriphagia that is the consumption of flowers as a food, is an old practice not widespread among consumers until some decades ago. Edible flowers contribute to increasing the appearance of food. They can provide biologically active substances including vitamin A, C, riboflavins, niacin, minerals such as calcium, phosphorous, iron and potassium that are eventually beneficial to consumers' health. This review includes some examples of edible flowers including roses, violets and nasturtium among others, uses and applications, sensorial characteristics and nutritional values that lead them to be considered as functional food: An important factor that affects the quality of edible flowers is the form in which they are preserved since it may affect their sensorial and nutritional characteristics. However, not all flowers can be eaten as food since there are some of them that can be toxic or even mortal. Finally, although the consumption of flowers is an ancient practice, there is little regulation in this regard. Of the review on edible flowers, it is concluded that there are still numerous aspects about them to evaluate such as nutritional and functional characteristics, conservation and regulation with the aim to extend its consumption.

Spices are aromatic plants that have been widely used in Mexico to preserve or seasoning different foods, but have also been used as herbal remedies to cure some diseases. These culinary and medicinal properties of spices have been attributed to several food components, including phytochemicals. Among them, polyphenolic compounds have been extensively studied for their effect against several chronic and degenerative diseases, probably due to their antioxidant activity. The study of the antioxidant capacity of Mexican spices may lead to new research on the potential benefits of these spices on human health. This paper analyzes the main studies on the potential beneficial effects of traditional Mexican spices on human health., (Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.)

Tropical roots and tubers (TRT) are important staple foods in the tropics. TRT are produced by small farmers and have received only limited attention. The objective of this paper was to evaluate nutritionally important carbohydrate fractions and proximal composition of cooked cassava (Manihot esculenta), cocoyam- or tannia- (Xantosoma sp) and yam (Dioscorea alata) grown in Costa Rica. Twenty boiled samples of each TRT were analyzed for proximal composition, following AOAC protocols. Carbohydrate fractions (dietary fiber, available and resistant starch) and alpha-amylolysis rate were assessed by enzymatic methods. All TRT analyzed consisted mainly of water and carbohydrates, representing moderate dietary fiber and energy sources. They show a low protein level and contain no fat. Moisture, protein, ashes and dietary fiber contents vary significantly (p<0.01) among the three species. In terms of their proximal composition, these locally grown TRT differ from TRTs cultivated in the South Pacific area, but appear similar to other Latin American varieties. In all samples most of the dietary fiber (84-88%) is insoluble; available starch ranges between 74 and 84% of the dry matter, whereas resistant starch content varied between 0.7 and 1.7%. Amylolysis rate was similar for cassava and cocoyam, whereas a significantly slower digestion (p<0.01) was recorded for yam. Compared to values reported in the literature for other starchy foods and to gelatinized potato starch, used as reference sample, the studied TRT showed intermediate amylolysis rates. It is concluded that consumption of these TRT may be promoted in Costa Rica and other countries with a similar nutritional situation.

The protein quality of fruits bodies of three Pleurotus ostreatus Mexican strains (INIREB-8, CDBB-H-896 and CDBB-H-897) was evaluated. The protein concentration (Nx4.38) ranged from 17.26 to 19.97 g/100 g dry weight; chemical scores were between 74 and 93% with available lysine as a first limiting amino acid in either INIREB-8 and CDBB-H-896 strains or leucine in CDBB-H-897 strain. The nutritional evaluation revealed 67.75 to 68.38% in vitro digestibility. Relative protein values were from 100.06-107.85%, which were lower than soybean meal and whole egg but larger than those of rice, maize, beans, fava beans and pasta, no differences were found between these values and those of skim milk powder, casein plus methionine and albumin. In accordance with the last results we concluded that due to their essential amino acids content, mushroom proteins are a good complement of cereals; furthermore, it is highly recommended to include Pleurotus in the daily diet.

Great amounts of agroindustrial wastes rich in polysaccharides, such as pectic substances, are produced worldwide. Some of these wastes are used for the production of pectin. Currently, pectin is extracted at industrial scale by physicochemical means, but lately new biotechnological alternatives have been developed. In this review, the principal characteristics of pectic substances and pectic enzymes are described. The traditional physicochemical method for the pectin extraction is described and the new biotechnological (microbial and enzymatic) methods for pectin extraction are discussed and commented as well.

The physicochemical properties of the six sources of dietary fiber more commonly consumed in Mexico were studied. The knowledge of these properties may allow a prediction of the functional effect of the fibers on the GI tract. The content of dietary fiber varied from 43% in wheat bran (WB) to 87% in Psyllium plantago (PP). Glucomannan (GM) showed the highest proportion of soluble fiber (97%) followed by dried cactus from Opuntia sp (DC) (28%) and PP (13%), whereas WB and soy isolate (SI) showed the highest proportion of insoluble fiber (95 and 92%, respectively). PP and GM showed a higher water holding capacity and viscosity and a lower ion exchange capacity: we anticipate that these fibers would be more effective to regulate plasma levels of glucose and cholesterol in contrast, WB and SI with a lower water holding capacity and viscosity and a higher proportion of insoluble fiber would be more effective to increase fecal bulk. Fibers from DC and from cactus fiber isolate were intermediate in these responses.

Characteristics and distribution of six plants are described. The chemical composition and in vitro digestibility of leaf and stem of Polymnia maculata, Trigonospermum annuum, Buddleia parviflora Kunt, Canna indica L, Gnaphalium oxyphyllum y Saurauia scabrida Hensl., selected for farmers information, were analysed as a potential resources in animal feeding. The results in dry matter: Crude protein (%): Go and Ss 10.9, Bp 16.7, Pm 11.7 and Ta 11.3. Cell wall (%): Go 54.1, Ss 52.3, Ci 54.4, Bp 68.3, Pm 27.8 and Ta 30.9. Lignin (%): Go and Ss 16.6, Ci 15.5, Bp 10.4, Pm 10.6 and Ta 13.3. IN vitro dry matter digestibility (%): Go 55.1, Ss 37.6, Ci 55.4, Bp 46.5, Pm 82.4 and Ta 81.4. Calcium and phosphorus (mg/100g) respectively: Go 1095 and 379, Ss 1132 and 387, Ci 600 and 421, Bp 800 and 855, Pm 1146 and 421 and Ta 905 and 480. Tannic acid (mg/100g): Go 1450, Ss 1480, Bp 575, Ci 518, Pm 3329 and Ta 2760. Trypsin inhibitor (UIT/g): Go 22264, Ss 29720, Bp 755, Ci 4228, Pm 931 and Ta 4412. Hemagglutinins were detected in Pm and Ta. Alkaloids were detected as scarce in Bp, Ci and Pm, moderate in Ta. Saponins and Cyanogenic glucosides were not detected. It is concluded that Pm and Ta could be considered as a forage for ruminants; Go, Bp and Ci as a complement; recommended the voluntary intake, in vivo digestibility and weight increase trials.

The difficulties inherent to provitamin A determination and the present state of development of the analytical methodologies are appraised. The procedures, the advantages and disadvantages and the possible sources of error of the methods involved are discussed. Open-column methods are still the most viable option in developing countries but the efficiency and reproducibility of the chromatographic separation depend largely on the analysts skill and experience. Although HPLC chromatograms are highly reproducible, the problem is to transform the peak areas to provitamin A concentrations because of the instability, varying purity and unavailability of provitamin standards. Internal standardization with the stable Sudan appears to be a promising solution. Separation of cis-isomers requires rechromatography in open-column systems. For HPLC, this problem still remains to be solved. Confirmation of the identity of the provitamins and prevention of degradation during the analysis are also dealt with. Notwithstanding the obstacles involved, reliable data can be obtained with adequate application of the analytical techniques and proper interpretation of the results.

The study of Atriplex suberecta leaf protein concentrate has been included within our work line entitled "Biological value of the leaf protein of Atriplex" amino acid profile and chemical score. In order to evaluate nitrogen retention, net protein utilization (NPU), true digestibility (TD) and biological value (BV) data were obtained. Weight gain was studied after determining net protein ratio (NPR) and relative net protein ratio (RNPR) with the following results: CS = 96, calculated for sulphur amino acids; NPU = 60 +/- 4.00; TD = 76 +/- 5.20; BV = 87; NPR = 3.34 +/- 2.50 and RNPR = 88%, which enable us to infer that its protein is of good quality. These data, therefore, should indicate that the product studied could be a good complement for cereals, considering its high lysine content (CS superior to 100).

An analysis of tuber roots yield and nutritional characteristics for 10 lines of jícama (Polymnia sonchifolia Poepp et Endl.) was carried out under the environmental conditions of Santa Catalina Experimental Station (12 degrees C of temperature and 3,100 m above sea level). The following average mean values were obtained: A fresh tuber root's yield from 29,755 to 73,558 kg/ha with 41,547 kg/ha of average, while the yield of the useful part (roots without skin) was from 24,309 to 60,097 kg/ha with 33,944 kg/ha of average. On the other hand, average mean values of 3.7% of protein, 3.5% ashes, 1.5% fat, 3.4% fiber, 2.2% potassium, 0.12% phosphorus, 96 micrograms/100 g iron, and 390 micrograms/100 g zinc, were obtained from the edible root samples. Besides, we obtained average values of 2.47, 2.12, 1.63 and 2.51 g/100 g of fructose, alfa glucose, beta glucose and saccharose, respectively, on edible root samples with skin, for the 10 lines studied. All these analyses were reported on a dry basis.