Scientific Papers Series B Horticulture

the increasing the CO 2 content and also ofair relative humidity - storage in modifiedatmosphere - MA.The duration of the storage (days) variedaccording to the technological variant, being of5 days for the warm storage, 25 days for thecold storage and 30 days for the AM storage.Before entering the storage period and at its endthe fruit were analysed in order to establish thefirmness, the organoleptic characteristics and thebiochemical features of the main components(dry soluble substance, soluble carbohydrates,titratable acidity). Moreover, the weight losses(quantitative) and those cause by alteration(qualitative) suffered by the fruit throughoutthe storage period were established.The firmness was determined by means of anOFD mass penetrometer which measures inpenetrometric units (1PU=0.1 mm) the depth thatthe conical needle (length=24 mm, base diameter= 4 mm) reaches within the pulp of the fruit.The measurements were carried out on a numberof 25 fruit/variant, each fruit being penetratedin 4 different points in the equatorial area.The appreciation of the organoleptic qualitywas achieved by means of carrying out asensorial testing of the fruit and the methodwas that of evaluating on a scale from 1 to 100.Tasting sheet were used comprising threeappreciation criteria: aspect, texture, taste. Eachof the three criteria holds a different weightwithin the general scoring, according to theirimportance. Thus, the “aspect” represents 15%,the “texture” 35% and the “taste” 50%.According to the scores there are five differentquality classes as follows:Grades (quality classesPointsVery good 80 – 100Good 60 – 79Acceptable 40 – 59Mediocre 20 – 39Unsuitable 0 – 19The methods for determining the biochemicalcomponents were the following: refractometry,using an ABBE refractometer to determine thesoluble substance, the Bertrand titrimetricmethod for determination of the solublecarbohydrates, the titrimetric method for thedetermination of the titratable acidity.During storage the thermo-hydric factors in thecold room were checked every day in order to15ensure that the optimum conditions for maintainingthe quality were respected. In addition,the capacity of maintaining the fruit’s qualitywas evaluated, including the apparition anddevelopment of certain storage diseases.RESULTS AND DISCUSSIONS1. FirmnessThe results presented in Table 1 reveal the factthat at harvest the firmness of the nectarinesranges from 68.79 PU at the V4 fertilisingvariant (chemical fertilisers applied on soil +foliar) to 93.57 PU at the V3 variant (chemicalfertilisers applied on the soil), the average percultivar being of 83.56 PU. Table 1. The firmness of the nectarines of the Deltacultivar upon harvesting and after storageMoment ofVariant Average/evaluation V1 V2 V3 V4 cultivarAt harvest 91.28 80.59 93.57 68.79 83.56After warm153.40150.11175.62144.11 155.81storageAfter cold storage 110.91129.35126.35127.95 123.64After AM storage 99.35 119.78123.66125.53 117.08During warm storage for 5 days the firmnessrapidly declines due to the alteration of thepectin substances and the cellular membranes,reaching values ranging from 144.11 PU at theV4 variant to 176.62 PU at the V3 variant, theaverage per cultivar being of 155.81 PU.Cold storage slowed down the structural andcellular alteration of nectarines, after 25 daysthe average firmness being of 155.81 PU,meaning 110.91 PU at the V1 variant, 126.35PU at the V3 variant, 127.95 PU at the V4variant and 129.35 PU at the V2 variant.The enriching of the atmosphere in carbondioxide allowed for the nectarines to be storedfor 30 days while maintaining the firmness atan average level of 117.08 PU, varyingbetween 99.35 PU at the V1 variant and 125.53PU at the V4 variant.2. The organoleptic qualityAt harvest, following the organoleptic test, thenectarines obtained a high score (89.95) due totheir lovely aspect, their high degree offirmness and their pleasant and balanced taste,thus entering the “very good” fruit quality class(Table 2).