MASS LOSSES OF POTATO INTENDED FOR PROCESSING DUE TO PHYSIOLOGICAL PROCESSES|
Sorin VÂTCĂ, Gavrila MORAR
University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture 3-5, Mănăştur Street, 3400, Cluj-Napoca, Romania (contact email: firstname.lastname@example.org)
In the context of European integration, superior capitalizations of farm product join through the priorities activity.
The processing of the potato through industrialization under form of finite product (chips, french-fries) is a superior form by capitalization which assures economical and financial advantages.
Echelon processing of potato production presume the conservation of that production for a 6-9 months, last period at the high temperature over 10oC determined by starch hydrolyze at lower temperature in simple sugars, which can modify the aspect and the taste of the final product
When the temperature is bigger then 10oC, the physiological process is accelerated (respiration - transpiration) concomitantly with those by germination causing important tubers mass wastage.
Material and methods
The research was carried out in 2001-2002 at five potato varieties: Ostara, Sante, Desiree, Roclas and Romano, on the tubers which have approximately same size (90-100 g) and same physiological age. For each variant were used 5 tubers, each tuber constituting a repetition. The determination was made monthly through sprout by weighing the sprouts and the tubers separately, mass wastage being establish through difference by one stage to another, both for sprout and for physiological process of respiration-transpiration from tubers.
For the step analysis of the processing two variants were used until by storage: one November-December after exit of the tubers from dormancy storage and another until February, to which date tubers were stored normally without sprout growth at temperature between 2 and 4oC.
Results and discussion
In the storage conditions of tuber until December for industrial processing the rhythm of mass wastage of tubers grows progressively at the beginning period for each variety with a maximum in the month January-April (table The mass wastage is very big at all varieties (38-57%), and the differences between varieties are less obvious, the biggest mass wastage being at the early and earlier varieties Ostara and Sante (57% respectively 45%).
The weight loses of the tubers extracted from storehouse in February follow the same intensity and same rhythm by decreasing in weight like those stored from November (table 2) and here the percentage of the wastage registering very high values (26-44%).
Table 1.The monthly mass wastage of potato tubers because of physiological process respiration-transpiration during the period 20.11.2001-21.06.2002 (g/tuber)
| ||Monthly's interval|| |
Table 2. Physiological process respiration-transpiration monthly's wastage in weight of potato tubers, during the period 13.02-15.07.2002 (g/tuber)
| ||Monthly's interval|| |
The total mass wastages of tubers because of the physiological processes by respiration-transpiration are described in graphical representation by ascending curves almost linear, that reflect the rapidity and the gravity of the mass wastage of potato in condition of high temperatures, in the conditions which the potato tubers for industrial processing under form of chips and french-fries are exposed a long period by time at this mode of storage. The wastage are extremely big and serious at all the varieties if the storage lasts more than one month (figure 1).
Figure 1. Weighting cumulated wastages of potato tubers because of physiological processes stored at 10oC
The mass wastage of tubers stored 3-4 month at high temperature over 100C, because of physiologically processes are very big as compared with the wastages because of germination.
Differences of mass wastage was observed also between varieties, the early and earlier one having wastages bigger than later varieties.
Because of physiological wastage in potato mass for industrial processing it is necessary that each factory have a storehouse were the storage factors may be controlled, raw material will be stored at low temperatures, and the rise of temperature in view of industrial preservation, will be made just one moth before potato processing.
Mureşan S., 1965, Cercetări privind repausul germinal şi pierderile prin păstrare la soiurile de cartof raionate, Analele ICCPT Fundulea, vol. XXXIII, seria C, p. 321-330
Mureşan S., Donescu V., 1984, Influenţa soiului şi a metodei de depozitare asupra păstrării cartofului, Analele ICPC Braşov, vol. XIV, p. 199-206
Rastovski A., Van ES A., et al., 1981, Storage of potatoes, Pudoc Wageningen, p. 99-128