ABSTRACT The objective of this work was to evaluate the post-harvest quality and the final storage time of the hydroponic crisp lettuce ‘Brida’, conditioned in different types of plastic packaging and environments. The statistical design was a completely randomized 3x2 factorial design, with 3 types of packages (control (without plastic packaging), perforated plastic packaging and closed plastic packaging) and 2 types of environments refrigerated (± 5 °C) and non-refrigerated (± 23 °C). Fresh leaf weight loss, relative SPAD content, total soluble solids content (TSS), pH, total titratable acidity (TTA), chlorophyll a and b, carotenoids and final storage time were measured. There was a decrease in the parameters of fresh mass, acidity, total soluble solids, and relative content of SPAD chlorophyll in refrigerated lettuce compared to uncooled. The use of packages also influenced post-harvest quality and closed packs resulted in lower values. It is concluded that the post-harvest quality of lettuce is better when they are refrigerated and packed in sealed packages.

A alface (Lactuca sativa L.) é a hortaliça folhosa mais consumida na alimentação do brasileiro, sendo boa fonte de vitaminas e de sais minerais. É largamente produzida no sistema convencional. No entanto, o cultivo hidropônico vem ganhando espaço no mercado, conquistando a confiança dos consumidores, cada vez mais exigentes com a qualidade dos alimentos. O objetivo deste trabalho foi avaliar o desempenho de duas cultivares de alface, nos sistemas de cultivo hidropônico e convencional, para a produção de massa fresca (MF) e massa seca (MS), fotossíntese, teores de antocianinas e de clorofilas. Foram conduzidos dois experimentos: um no sistema de cultivo hidropônico (CH) e outro em cultivo convencional (no solo) (CC), realizados em ambientes protegido e desprotegido, respectivamente, no município de Florianópolis, SC. A cultivar Mimosa Verde (MV) apresentou maior peso de massa fresca, em comparação com Mimosa Roxa (MR), em ambos os sistemas de produção, e ambas as cultivares apresentaram melhor desempenho no sistema hidropônico (287,7 g MV e 139,1 g MR), em relação ao convencional (129,7 g MV e 111,8 g MR). A cultivar MV apresentou menores teores médios de clorofila total (7,7 mg g-¹ MF), quando comparada com MR (11,8 mg g-¹ MF) e ambas apresentaram teores médios mais elevados dessa variável no cultivo hidropônico. Para a cultivar MR, os teores de antocianinas, no cultivo convencional, foram superiores (88,24 mg g-¹ MF) aos do cultivo hidropônico (36,89 mg g-¹ MF). Os melhores resultados para a taxa de assimilação líquida de CO2, com relação à densidade de fluxo de fótons fotossinteticamente ativos, foram observados no cultivo hidropônico, para ambas as cultivares. Também se observou variação nos teores de clorofila, que foram maiores no ambiente protegido do sistema hidropônico, e antocianinas, que foram maiores no cultivo convencional.

Lettuce (Lactuca sativa L.) is the most commonly consumed leaf vegetable in the Brazilian diet, and it is a good source of vitamins and minerals. It is widely grown in the conventional farming system. However, the hydroponic farming system has been gaining importance in the market, wining confidence from consumers, who are becoming increasingly more demanding on food quality. The objective of this study was to evaluate the performance of two lettuce cultivars on hydroponic and conventional farming systems for the production of fresh mass (FM) and dry mass (DM), photosynthesis, contents of chlorophyll and anthocyanin. The following two experiments were carried out: hydroponics farming (HF) and conventional farming (CF), performed in protect and unprotect environments, respectively, in Florianópolis, SC. Mimosa Verde cultivar (MV) showed greater fresh mass than Mimosa Roxa (MR), in both farming systems and the two cultivars presented better performance in the hydroponic system (287.7 g MV and 139.1 g MR) than the conventional system (129.7 g MV and 111.8 g MR). Mimosa Verde cultivar presented lower average contents of total chlorophyll (7.7 mg g-¹ FM) than Mimosa Roxa (11.8 mg g-¹FM), and both cultivars displayed higher means for this variable in the hydroponic farming system. Mimosa Roxa presented higher contents of anthocyanin in the conventional system (88.24 mg g-¹ FM) than the ones in the hydroponic system (36.89 mg g-¹ FM). The best results for CO2 net assimilation rate regarded to photosyntheticaly active photon flux density were found in the hydroponic system, for both lettuce cultivars. Variation in the contents of chlorophyll were also found. Those variations were higher in the protected system than in the hydroponic system and contents of anthocyanin were higher in the conventional system.

Com o objetivo de avaliar a qualidade nutricional de cinco cultivares de alface (Mimosa Verde, Mimosa Vermelha, Vera, Regina e Lucy Brown) produzidas em cultivo hidropônico sob sistema NFT, determinou-se sua composição centesimal e seu teor de nitrato. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. O experimento foi desenvolvido no Departamento de Engenharia Rural da Universidade Federal de Santa Catarina, Florianópolis (SC), de maio a julho de 2004. As bancadas de produção possuíam sete canais com 6,0 m de comprimento e 1,50 m de largura. O espaçamento utilizado foi 0,25 m e canais e 0,25 m entre plantas no canal. A colheita foi efetuada aos 54 dias após a semeadura, e permanência por 24 dias na bancada de produção. Na cultivar de alface do tipo americana, Lucy Brown, observou-se maior teor de água da parte aérea e também maior teor de nitrato. Nas cultivares Mimosa Vermelha e Mimosa Verde verificaram, em média, maior teor de fitomassa seca da parte aérea, de lipídios, de proteína e maior valor calórico. Na cultivar Mimosa Vermelha constatou-se maior teor de carboidratos e na Mimosa Verde, o maior teor de resíduo mineral, não diferindo da cultivar Regina. O maior teor de fibra foi constatado na cultivar Regina.

The nutrition quality of five different lettuce cultivars (Mimosa Verde, Mimosa Vermelha, Vera, Regina and Lucy Brown) produced under NFT (Laminar Flow of Solution) system was determined by their centesimal composition and nitrate content. To analyze the experimental treatments it was used a completely randomized design with four replications. The experiment was developed in a greenhouse belonging to the Department of Agricultural Engineering of the Federal University of Santa Catarina, Florianópolis, Santa Catarina State, Brazil, from May to July of 2004 (autumn-winter period). The lettuces were grown in a group of benches (3% declivity) with seven canals (6.0 m length and 1.50 m width) where the nutritional solution would circulate. The space used was 0.25 m between canals and 0.25 m between plants in the canal, thus in each canal 24 plants had been lodged, totalizing 168 per bench. The circulation of the nutritional solution was controlled by a timer, which set in motion the joint motion-bomb in intervals preset in a turn 24-hour. The harvest was effected 54 days after the sowing, having remained per 24 days in the production group of benches. The American type of lettuce 'Lucy Brown', also presented a greater water content in its shoot as well as nitrate content than the others. Mimosa Vermelha and Mimosa Verde cultivars had on average, greater dry mass content theirs of shoots, as well as lipids, protein and caloric value than the others. 'Mimosa Vermelha' presented greater carbohydrates content and 'Mimosa Verde' the greater mineral residue content, but not differing from Regina cultivar. The biggest fiber content was presented by 'Regina'.

O cultivo de microalgas representa uma potencial fonte de biomassa rica em clorofila e sais minerais como: fósforo, ferro, manganês, cobre, zinco, magnésio e cálcio. Este experimento teve como objetivo avaliar a composição de minerais, bem como determinar o teor de clorofila a e b da microalga Chlorella vulgaris cultivada em solução hidropônica residual em três diferentes concentrações comparadas com um cultivo controle. Os resultados mostraram que os teores de clorofila a e b da microalga não apresentaram diferença significativa entre os cultivos. Com relação à composição dos sais minerais, a Chlorella cultivada na solução residual mais concentrada apresentou valores superiores quando comparada com a cultivada nos demais cultivos. Dessa forma, a biomassa da Chlorella vulgaris demonstrou ser uma potencial fonte de clorofila e de sais minerais, quando cultivada em solução hidropônica residual, possibilitando a utilização desse resíduo de forma sustentável.

The microalgaes cultive represents a potential source of biomass rich in chlorophyll and minerals as: P, Fe, Mn, Cu, Zn, Mg and Ca. This research was aimed at evaluating the composition of minerals, as well as, determining the content of chlorophyll a and b from the microalgae Chlorella vulgaris cultivated in hydroponic wastewater in three different concentrations compared with the control cultive. The results showed that the contents of chlorophyll a and b of the microalgae did not show significant difference between the cultives. In relation to the composition of the minerals, the Chlorella cultivated in the most concentrated wastewater, showed higher values when compared with the one cultivated in the others cultures. In this manner, the Chlorella vulgaris biomass demonstrated to be a potential source of chlorophyll and minerals, when cultivated in hydroponic wastewater, allowing the use of this residue in a sustainable way.