Guavas cv.`Kumagai' were packed in several plastic materials and stored at 10°C and 85±90% relative humidity (RH) for 7, 14, 21 and 28 days (3 days at 25°C). The plastic materials studied were: multilayer co-extruded polyolephine ®lm with selective permeability (PSP), low-density polyethylene ®lm (LDPE), LDPE ®lm with mineral incorporation (LDPEm) and heat-shrinkable polyolephine ®lm (SHR). Guavas not packed were taken as control samples. The physicochemical characteristics of the fruits, O 2 and CO 2 transmission rates of the packaging materials and gas composition at the package headspace were evaluated. The LDPE ®lm, 69 mm in thickness, with the lowest permeability to both O 2 and CO 2 , led to anaerobiosis and high CO 2 concentration inside the packages and promoted physiological disturbances and changes in fruit¯avour. The SHR ®lm, 15 mm in thickness, was the most permeable to CO 2 and had quite high O 2 transmission, which modi®ed the inner atmosphere of the packages slightly. The fruits packed in this ®lm showed a poorer quality than the controls, possibly due to the heat produced during the shrinking of the ®lm. The LDPEm ®lm, 24 mm in thickness, was almost as permeable to CO 2 but had reduced O 2 transmission, promoting an atmosphere of equilibrium of 3% O 2 and 4.5% CO 2 . Fruits packed in this ®lm kept their skin colour and pulp ®rmness, suitable for consumption up to 14 days. The PSP ®lm, 35 mm in thickness, had the greatest O 2 transmission but just over half of the CO 2 transmission of LDPEm, promoting an atmosphere of equilibrium of 0.5% O 2 and 4.5% CO 2 inside the packages. Fruits packed in such packages kept their physicochemical characteristics up to 21 days.

Um experimento foi desenvolvido em Agudos (SP), num Argissolo Vermelho-Amarelo, com o objetivo de avaliar o efeito do parcelamento da adubação NPK em abacaxizeiro 'Smooth Cayenne'. Foram estudados os seguintes esquemas de fracionamento da adubação NPK: T1 (testemunha) -- N e K parcelados em quatro aplicações (60 kg ha¹ de N e de K2O em jun/95; 120, em nov/95; 250, em jan/96 e 120, em mar/96); T2 -- N e K parcelados em quatro aplicações (60 kg ha¹ de N e de K2O em jun/95; 120, em nov/95; 160, em jan/96 e 210, em mar/96); T3 -- N e K parcelados em três aplicações (90 kg ha¹ de N e de K2O em jun/95; 180, em nov/95 e 280, em jan/96); T4 -- N e K parcelados em cinco aplicações (60 kg ha¹ de N e de K2O em jun/95; 110, em nov/95; 160, em jan/96; 110, em mar/96 e 110, em maio/96); T5 -- diferiu do T1 pelo número maior de aplicações de K (cinco) e, do T4 pelo menor número de aplicações de N (quatro); nesses cinco tratamentos (T1 a T5), todo o P foi aplicado no plantio (maio/95); T6 -- N e K parcelados como no T1 e P em duas aplicações (50% no plantio e 50% em jan/96). Os frutos, colhidos 21 meses após o plantio, tiveram sua massa média e qualidade influenciadas pela forma de parcelamento da adubação com N e K; de outro modo, o fracionamento da adubação fosfatada não influenciou a produção. O parcelamento com aplicação mais tardia de N (cinco aplicações, até 12 meses após o plantio-T4) aumentou a produção, contudo, teve efeito negativo sobre o teor de sólidos solúveis dos frutos.

No abstract

Guavas cv. Kumagai fruits were packed in plastic bags and stored at 10°C and 85-90% RH during 7, 14, 21 and 28 days, followed by open exposure for 3 days at 25°C and 70-80% RH to simulate commercial handling conditions. The packaging materials used were: multilayer coextruded polyolefin film with selective permeability (PSP), low density polyethylene film (LDPE), LDPE film with mineral incorporation (LDPEm) and heat-shrinkable polyolefin film (SHR). Guavas without plastic packages were used as control samples. The concentrations of O 2 and CO 2 in the package headspace and the sensorial characteristics of the guavas (skin color, pulp texture, off-flavor and overall quality) were evaluated. The LDPE film presented the higher gas barrier and promoted the lowest O 2 level (0.1%) and the highest CO 2 concentration (19%) inside the packages. Such passive modified atmosphere induced both off-flavor and abnormal ripeness. The polyolefin heat-shrinkable film provided poor modification in the package atmosphere, so the fruits exhibited fast senescence (decay). The film incorporated with mineral provided an atmosphere of 3% O 2 and 4.5% CO 2 Downloaded from inside the packages, which kept the fruit with good sensorial characteristics for 14 days. The coextruded polyolefin film provided an atmosphere of 0.5% O 2 and 4.5% CO 2 that was sufficient to maintain the fruit with good sensorial characteristics for 28 days.

Aos meus pais José (in memoriam) e Ruth, pelos ensinamentos, amor, dedicação e, sobretudo, exemplo de vida...; À minha irmã Maria José, pelo constante apoio, incentivo e compreensão, DEDICO.

The objective of this study was to evaluate the influence of package materials on the preservation of cold-stored 'Kumagai' guavas. The treatments were: PO2, coextruded polyolephinic film with gas injection (5% O 2 /5% CO 2 /N 2 ); PO3, coextruded polyolephinic film with gas injection (5% O 2 /5% CO 2 /N 2 ); LDPE, linear low density polyethylene film; LDPE-gas, linear low density polyethylene film with gas injection (3% O 2 /8% CO 2 /N 2 ); PVC, polyvinylchloride stretch film; PO1, co-extruded polyolephinic film and control: non-packaged guavas. Guavas were stored at 10 ± 1°C/80-90% RH for 21 days, and then transferred to room temperature. Gas composition within the package headspace was analysed during storage and the physical and chemical characteristics of the guavas were evaluated daily during ripening. The modified atmosphere provided by PO1 film was insufficient to promote the benefit of senescence control. Although PVC provided an atmosphere close to that recommended, it did not preserve the colour and pulp firmness. PO2, PO3, LDPE and LDPE-gas retarded the senescence process of the guavas during 21 days at 10°C plus 2 days at room temperature, but harmed the normal ripening of guavas in some aspects. This can be explained by reduced O 2 and elevated CO 2 levels within these four packages. None of the packages influenced the titratable acidity and the soluble solids, but they did harm ascorbic acid synthesis. INTRODUCTIONGuava is a perishable fruit with a short shelf-life when stored at room temperature. The use of preservation methods that can increase guava shelf-life whilst-maintaining quality is desirable. In climacteric fruits, reduction of temperature retards the climacteric and consequently the ripening process. 1 The recommended storage temperature for guavas is 9-10°C in order to avoid chilling injury. 2,3Many studies have evidenced the efficiency of plastic packages on guava preservation by reducing the ripening and weight loss.4-6 Guavas could be stored for 2 weeks when packed in polyethylene films impregnated with humidity-absorbent mineral.7 'Kumagai' guavas could be conserved in sealed polyethylene packages for 3 weeks at 8°C. 8The major reason for using modified atmosphere packaging is that the low O 2 and high CO 2 concentrations reduce the respiration rate and consequently slow down quality loss. Concentrations below 8% O 2 and/or above 3% CO 2 reduce ethylene production and sensitivity. 9 Atmosphere modification within a package can occur passively, as the product consumes O 2 and discharges CO 2 , or can be promoted actively by vacuum followed by gas mixture injection. In both cases, the package permeability must be compatible with the vegetal respiration rate, maintaining an appropriate atmosphere for a better conservation. 10The objective of this work was to evaluate the influence of package materials, associated or not with active atmosphere modification, on the preservation of cold-stored 'Kumagai' guavas. MATERIALS AND METHODS'Kumagai' guavas (Psidium guajava) were harvested from ...

EFFECT OF NAPHTHALENE ACETIC ACID AND CALCIUM CHLORIDE IN REDUCING POSTHARVEST LOSSES OF 'NIGARA ROSADA' GRAPES ABSTRACT -, with and without the use of 10g L -1 CaCl 2 were tested. The different concentrations of NAA were applied the day before harvest; meanwhile CaCl 2 was applied at the beginning of the berry ripening. Right after harvest, the grapes were evaluated for total soluble solids, titratable acidity, pH, percentage of abscission post-harvest and decay incidence. The grapes of the different treatments were stored under two conditions: 25°C/70% RH for 5 days and at 1°C /85% RH for 21 days followed by storage at 25°C/70% RH for 5 more days. At the end of each storage period, the grapes were evaluated for the same variables. The results indicate that application of NAA was effective in reducing the percentage of drop berries and the incidence of decay, mainly in those fruits stored at 25°C/70% RH, being the concentration of 150 mg.L -1 the most effective. The treatments did not cause significant differences on total soluble solids, pH, and titratable acidity.

As duas variedades de abacaxizeiro cultivadas comercialmente no Brasil, Smooth Cayenne e Pérola, são altamente suscetíveis à fusariose. Com o objetivo de caracterizar as variedades existentes para boa utilização no melhoramento genético, desenvolveram-se, de maio/91 a fevereiro/94, em Cordeirópolis (SP), quatro experimentos, cada um com um tipo de muda de abacaxizeiro, a saber: tipo "filhote", "rebentão", "coroa" e "gema", esta obtida pelo brotamento, em areia, de gemas da haste da planta. As variedades estudadas foram: Rondon (RD), Roxo de Tefé (RT), Turi Verde (TV), Natal Queen (NQ), Guiana (GN), Pérola (PR) e Smooth Cayenne (SC). Semanalmente, em cada planta, avaliaram-se os estádios de desenvolvimento: emissão natural da inflorescência, início e final da emissão de flores e maturação dos frutos (colheita); a produção (massa) e os comprimentos dos frutos e de suas coroas; os diâmetros (o maior, o da base e o do ápice) dos frutos, e, na polpa, os teores de sólidos solúveis (grau Brix), a textura, a acidez titulável, os teores de ácido ascórbico (vitamina C) e o pH. As variedades Rondon e Pérola emitiram as inflorescências mais precoce e uniformemente que as demais, enquanto Cayenne e Turi Verde mostraram-se tardias. Na soma dos períodos dos três estádios de desenvolvimento da inflorescência e do fruto, isto é, da emissão da inflorescência até a colheita, `NQ' foi a mais precoce e `GN' e `RT', as mais tardias. `SC' e `GN' produziram frutos com massa média, em gramas, respectivamente, 52% e 24% superiores à média de `RD', `PR' e TV'; os frutos de `NQ' apresentaram massa inferior a todas as variedades. `GN' revelou a maior produção de mudas e `SC', a menor produção da muda tipo filhote. As plantas provenientes de muda tipo gema produziram menor número de mudas que as de filhotes, rebentões e coroas. Os teores de sólidos solúveis da polpa dos frutos de `SC' e de `NQ' e a acidez de `TV' alcançaram os maiores valores. O teor de vitamina C de `PR' foi o mais elevado e, o de `RD', superior ao de `SC'. `NQ' apresentou a mais alta relação grau Brix/acidez.
Seven pineapple varieties were tested in field trials in Cordeirópolis, State of São Paulo, from May 1991 to February 1994, in four experiments, each one using different planting materials: sucker or shoot, slip, crown and stem section plants (developed from bud stem in sand box). The varieties were: Rondon (RD), Roxo de Tefé (RT), Turi Verde (TV), Natal Queen (NQ), Guiana (GN), Pérola (PR) and Smooth Cayenne (SC).The followings characteristics were evaluated: the periods for natural inflorescence emission, the time between the emission until the flowering completed, and from then until the ripped-fruit; also, the fruit diameters (the base, the top and the largest diameter), the mass production (fruit and crown), and in the pulp, the soluble solid content (Brix), texture, acidity, ascorbic acid content and pH. The main results were: (1) RD and PR had the earliest uniform natural inflorescence emission, and SC and TV had the latest ones; (2) NQ had the shortest and S...