Cultivares de mandioca de mesa e idades de colheita: avaliação agronômica e adequação ao processamento mínimo

Abstract

The harvest of sweet cassava is usually set by the market price, even though there being early, semi-early and late sweet cassava. This can result in unsatisfactory yields. Cultivars of sweet cassava little studied as cv. Mossoró may be an alternative crop compared to those sold in the Sertão do Pajeú such as cvs. Rosinha and Recife since proper to the appropriate harvest age. In any case, these cultivars are no intended for minimum processing. To get new shapes called 'minimacaxeiras' is required to adapt the minimal processing procedures using “turner”, as well as the systematic immersion in cold water, since such immersion in cold water can facilitate peeling. The objective of this study was to evaluate the agronomic characteristics, quality and culinary; adequate procedures in the minimum processing and preservation of minimally processed sweet cassava cultivars and from different harvest ages in the Semiarid of Pernambuco. The experiment was conducted in the experimental area of the Academic Unit of Serra Talhada, UFRPE, from March 2011 to May 2012. In planting, cuttings of the cultivars' Mossoró ', Rosinha' and 'Recife' of approximately 15 cm in length, were planted at a density of 16,666 plants/ha-1. All plants present in the area were harvested at 8, 10, 12 and 14 months after planting and transported to the Center of the Graduate Program in Plant Production UFRPE-UAST. They were weighed, cleaned and cooled for 24 hours. After this period, they were cut into "oarlocks", immersed for 0, 5 and 30 minutes, peeled, cut to obtain the 'half-oarlock'. They were shaped by 30, 60 and 120 seconds, yielding the shape called 'Rubiene'. Then, the pieces of 'Rubiene' were sanitized with chlorine solution (dihydrate sodium dichloroisocyanurate) 200 mg L-1 of chlorine per 10 minutes and 5 mg L-1 for 10 minutes, centrifuged for 60 seconds at 2800 rpm; packaged in polypropylene bags 150 x 100 mm and 0.4 μm thick, sealed and stored at 5 ± 2º C for 11 days in refrigerated display. The cv. Mossoró excelled in some agronomic evaluations related to productivity as: Root Dry Mass, Final Stand, Yield and Numbers of Roots. Thus, cv. Mossoró was the one that most produced under the studied conditions and may be alternative crop for small farmers in the Sertão do Pajeú. Concerning to the minimal processing, immersion in cold water for 5 minutes before peeling, resulted in speed for peeling only when harvested at 10 months for the cvs. Mossoró and Recife. In the case of cv. Rosinha, immersion resulted in no significant gain in agility for peeling, regardless of the harvest period. The increased in turning time promoted lower agroindustrial yield, reduced the cooking time, since harvested at 10 months and minimized the browning. Thus, turning by 60 seconds was deemed most appropriate. The advance in harvesting age increased the productivity, facilitated the peeling, increased the yield and contributed to lower temperatures at harvest and minimum processing stages when that harvest coincided with cooler seasons of the year. Additionally, increased soluble solids, the cooking time and became the 'minimacaxeiras' less susceptible to browning. Thus, the harvest taken at 14 months resulted in satisfactory yields and it was more suited to the minimal processing conditions studied.