Evaluation and storage of green corn hybrids for the production of pamonha

Author(s)

Ana Carolina Leme

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2007-09-26

Examining board members

Silene Bruder Silveira Sarmento; José Francisco Lopes Filho; Marta Helena Fillet Spoto

• Advisor: Silene Bruder Silveira Sarmento

Abstract

The physicochemical characteristics of the hybrids of green corn for the production of pamonha and the effect of the raw materials storage on the quality of the final product are still not well known, but of great importance to the development of the agro-industry. The objectives of the present study were to evaluate hybrids of corn for the production of pamonha and the effects of the storage (ambient conditions and refrigeration) of these hybrids on the physical, physicochemical and sensory characteristics of pamonha. The hybrids evaluated were the AG1051, BM3061 and DOW8003. Newly harvested corn-cobs have been used to characterize the hybrids. They were evaluated with regard to physical and physicochemical characteristics and mass percentage. The processed pamonhas were also analysed regarding their physical, physicochemical and sensory characteristics (DQA). The grains of the three hybrids presented similarities with regard to composition (moisture content of 67.4% and soluble fibers of 0.3%) and color (luminosity 72, chroma a* -0.8 and chroma b* 33). The hybrids were statistically different (p<0.05) with regard to starch content (11.4 a 12.8%), soluble carbohydrates (0.8 a 1.6%) and insoluble fibers (2.2 a 2.8%). With regard to the pasting properties (RVA), the results presented wider differences: the peak viscosity varied between 202 and 314RVU and the setback, between 94 and 164RVU. The pamonhas prepared with the hybrids presented more variable composition, with pH between 7.1 and 7.5, moisture content between 63.6 and 65.9%, starch content between 5.0 and 5.4%, total soluble carbohydrates between 18.9 and 21.8%, soluble fibers between 0.3 and 1.0%, and insoluble fibers between 1.1 and 1.5%. The parameters of color were Luminosity (54.8 to 59.8%), chroma a* (-4.6 to -5.1) e chroma b* (20.5 to 29.6). The hardness (texture analyzer) varied between 804 and 1584N. In the sensory analysis, the grades varied from 5.7 to 6.3 for the yellow color, 4.2 to 5.8 for the creamy texture, 5.4 to 6.1 for the fibrous texture, 6.0 to 7.1 for the firmness and the general impression varied from 6.4 to 7.5. The effects of the storage of the hybrids with husks, at room temperature (25&#176; C and 80% UR) and under refrigeration (7&#176; and 98% UR), on the quality of the grains and pamonhas were assessed at 0, 3 and 6 days after the harvest. It is recommended the storage of the corn cobs for the production of pamonha under refrigeration (7oC) because this condition results in better maintenance of the physical and physicochemical characteristics of the corn and pamonhas. The products of the three hybrids stored at room temperature and under refrigeration received, in general, good grades by the provers, however, it was observed that the pamonhas produced with raw materials stored for 6 days were firmer and more fibrous, less creamy and with some yeasty flavour. It can be concluded that, apart from the variations due to the storage, there is variability within the hybrids and there must be interference of the processing in the characteristics of the products, mainly in the steps of formulation and boiling into water, besides of the type of packaging required. (AU)