Quantitative descriptive analysis of Italian polenta produced with different corn cultivars. Journal of the Science of Food and Agriculture, 92, 412-417

ArticleinJournal of the Science of Food and Agriculture 92(2):412-7 · January 2012with 217 Reads
DOI: 10.1002/jsfa.4593 · Source: PubMed
Abstract
Polenta is a porridge-like dish, generally made by mixing cornmeal with salt water and stirring constantly while cooking over a low heat. It can be eaten plain, straight from the pan, or topped with various foods (cheeses, meat, sausages, fish, etc.). It is most popular in northern Italy but can also be found in Switzerland, Austria, Croatia, Argentina and other countries in Eastern Europe and South America. Despite this diffusion, there are no data concerning the sensory characteristics of this product. A research study was therefore carried out to define the lexicon for a sensory profile of polenta and relationships with corn cultivars. A lexicon with 13 sensory parameters was defined and validated before references were determined. After panel training, the sensory profiles of 12 autochthonous maize cultivars were defined. The results of this research highlighted that quantitative descriptive analysis can also be used for the sensory description of polenta, and that the defined lexicon can be used to describe the sensory qualities of polenta for both basic research, such as maize selection, and product development.
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    The first genetically modified (GM) maize lines were approved for trading in Brazil after December 2007 and they were T25, MON810, Bt11, NK603 and GA21. The polymerase chain reaction (PCR) method was employed to monitor the presence of Bt11 and nested PCR was used to detect the presence of Bt176 in 81 maize-derived products (maize flour, corn meal, maize flour flakes and polenta) that were sold in Brazilian market from 2005 to 2007, before the release of GM maize in Brazil. The PCR detection limit for Bt11 was 10 g kg(-1) and for nested PCR of Bt176 it was 1 g kg(-1). All Brazilian samples analyzed showed no positive signal for these GM maize events. Bt11 and Bt176 GM maize lines were not detected by specific PCR in 81 maize-derived food samples sold in Brazil from 2005 to 2007, before the commercial release of GM maize in Brazil. These Brazilian food industries were in compliance with the rules stipulated by the current legislation with respect to consumer requirements about GMO labeling.
  • Article
    Knowledge of the association between cooking properties and endosperm hardness may help nutritionist and processors to select raw materials for preparing maize based food products, particularly those eaten as cooked dispersions. Seven commercial maize cultivars differing in hardness were selected to evaluate endosperm hardness on the kernels and some characteristics such as composition and hydration and cooking properties on the grits obtained from those maizes. Results show that the differences in endosperm hardness (directly related to grits protein content) can explain the differences in swelling and amylographic consistencies values. Cultivars with the hardest endosperm show the lowest values at high temperature. They also show the lowest amylographic consistencies. On the other hand softer endosperms present the highest swelling power and the highest amylographic consistencies. These differences are attributed to the restriction for starch swelling caused by the protein matrix. Endosperm hardness measurements and swelling power at 95 degrees C, can be useful to select cultivars that are going to be used to prepare maize based foods like atoles, polenta, etc.
  • Article
    Widely consumed by populations of all socioeconomic classes worldwide, corn is one of the few food sources of lutein and zeaxanthin. However, data on these carotenoids in processed corn and corn as eaten are lacking. Thus, the major carotenoids in the principal brands of processed corn (canned corn, corn meal, corn flour, corn flake) and in typical corn dishes (farofa, boiled corn, pamonha, curau, fried and boiled polenta) were determined. There was marked variation between processed products and between brands of the same product, but variation between lots of the same brand was small. Canned corn had the highest zeaxanthin (11.91 to 18.06 microg/g), beta-cryptoxanthin (2.32 to 3.77 microg/g), and beta-carotene (1.79 to 2.75 microg/g) contents. The corn flake breakfast cereal had the second highest amount of zeaxanthin (9.08 to 12.77 microg/g). Corn meal had the highest lutein (4.02 to 7.62 microg/g) level and also had good zeaxanthin content (6.13 to 11.39 microg/g), but drastic reduction of all carotenoids, especially zeaxanthin, occurred when it was toasted to farofa. Boiled corn also had lower carotenoid levels compared to the raw corn. The wide variations in carotenoid concentrations appeared to be due mainly to varietal differences in the carotenoid composition of raw materials and to losses during processing and preparation for consumption.
  • Profilo sensoriale, in Valutazioni sensoriali: aspetti teorici, pratici e metodologici
    • E Pagliarini
    • Metodi
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    28 International Organization for Standardization, Sensory analysis – General guidance for the design of test rooms. ISO 8589 : 2007 (2007).
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    26 International Organization for Standardization, Sensory analysis – Methodology – Initiation and training of assessors in the detection and recognition of odours. ISO 5496 : 2006 (2006).
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  • Maize for the production of polenta flour
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