Paulo Rogério Fontes

Effects of the addition of mechanically deboned poultry meat and collagen fibers on quality characteristics of frankfurter-type sausages

The effects of mechanically deboned poultry meat (MDPM) and levels of collagen fibers on comminuted, cooked sausage quality characteristics were investigated using the central composite rotatable design of response surface methodology (RSM). Use of collagen fiber as an additive affected the sausage characteristics, but the effect depended on the amount of the MDPM used. While MDPM additions resulted in higher cooking loss and darker and redder frankfurters, the addition of collagen fibers improved cooking yields and contributed to the lightness of the final product. Higher collagen fiber content was also accompanied by a significant increase in frankfurter hardness regardless of the MDPM content. Use of collagen fibers countered the negative effects of MDPM on sausage quality attributes, especially on cooking yields and final product color.

Qualidade do tomate em função de doses de nitrogênio e da adubação orgânica em duas estações

The tomato fruits quality, measured by pH, by total soluble solids, by the entitled total acidity and by the N-NO3- and total N content in the dry matter, as a result of nitrogen doses and organic fertilization, was evaluated in two field experiments, conducted in spring/summer (nov/98 to feb/99) and autumn/spring (may/99 to oct/99). The experiments were carried out in Vicosa, Minas Gerais State, Brazil. The N doses were 0,0 and 0,0; 93,5 and 110,0; 187,0 and 220,0; 374,0 and 440,0; and 748,0 and 880,0 kg/ha, in spring/summer and autumn/spring experiments, respectively, and the doses of organic matter in the form of hardened cattle manure, in dry base, 0 and 8 t/ha, in the experiments. The experimental design was of randomized blocks arranged in a 5x2 factorial design, with four replications. In the two periods, the pH, the total soluble solids and the entitled total acidity in tomato fruits did not alter with the increase of N doses, without and with cattle manuring; the N-NO3- content in the dry matter of the fruits increased linearly with the doses of N, without cattle manuring; in the presence of cattle manure this variable was not influenced by N doses.

Avaliação de genótipos de tomateiro cultivados em ambiente protegido e em campo nas condições edafoclimáticas de Viçosa

The influence of the temperature, air humidity, brightness and their effects on tomato yield growth in protected environment and in the field were evaluated. Two experiments were carried out in different atmospheres from January to May 2002. The cultivar Santa Clara, hybrid Carmen and an accession BGH-320 from the Germplasm Vegetable Bank of Universidade Federal de Vicosa, Minas Gerais State, Brazil, were used in both experiments. The experiment under protected environment was carried out in a greenhouse type chapel and the other in the field, under natural conditions. In general higher production of fruits was observed on plants cultivated under protected environment than in open field. The Carmen hybrid exceeded the other genotypes in yield in the protected environment. Accession BGH-320 presented lower total yield under protected environment than the other two genotypes. In the field the accession BGH-320 presented higher total yield than Santa Clara cultivar and a similar yield than Carmen. In the field, the commercial yield did not differ among the three genotypes.

Acúmulo de nutrientes e método para estimar doses de nitrogênio e de potássio na fertirrigação do pimentão

Neste estudo caracterizou-se as curvas de acumulo de nutrientes na parte aerea do pimentao (Capsicum annuum L.)e propos-se um metodo para estimar as doses de nitrogenio e de potassio para a fertirrigacao em cultivo em estufa nao aquecida. O experimento foi executado de marco a dezembro, no delineamento de blocos casualizados com seis repeticoes e 16 tratamentos. Cada tratamento correspondeu a uma epoca de amostragem, realizada a cada 14 dias apos o transplante (DAT) ate 224 DAT. Nesta data, as produtividades de frutos e de materia seca da parte aerea foram 51960 e 6135 kg ha-1, respectivamente. O acumulo de nutrientes na parte aerea do pimentao, expresso em kg ha-1, foi: 247 de K, 193 de N, 114 de Ca, 42 de Mg, 23 de P, 23 de S, 1,2 de Fe, 0,31 de B, 0,29 de Cu, 0,27 de Zn e 0,26 de Mn. Sao apresentadas as equacoes representativas da curva e da taxa diaria de acumulo (TA) para cada nutriente. Com base na TA e proposto um metodo para estimar as doses de N e K para cada fertirrigacao do pimentao em estufa nao aquecida.

Dinâmica do crescimento, distribuição de matéria seca e produção de pimentão em ambiente protegido

Caracterizou-se o crescimento, a particao de materia seca e a producao de pimentao, hibrido Elisa, em ambiente protegido. O experimento foi delineado em blocos casualizados com seis repeticoes e 16 tratamentos, de marco a dezembro, durante 224 dias a partir do transplante (DAT). As mudas foram transplantadas em 27/04, no espacamento de 1,0 x 0,6 m. Cada tratamento correspondeu a uma epoca de amostragem, realizada a cada 14 DAT. Em cada amostragem, foram avaliadas as caracteristicas relacionadas ao crescimento da planta e a producao de frutos maduros. A massa seca na parte aerea atingiu o maximo de 368 g planta-1, aos 224 DAT. As producoes de materia seca do fruto, caule e folhas aumentaram ao longo do tempo atingindo os valores maximos de 189, 79 e 109 g planta-1 aos 224 DAT, respectivamente. Da mesma forma aconteceu com a area foliar por planta, altura da planta e a taxa de crescimento absoluto, cujos valores maximos foram 9056 cm2, 91 cm e 4,11 g m-2 dia-1, respectivamente. Conclui-se que o crescimento da planta foi continuo ao longo do ciclo sendo que os frutos acumularam a maior quantidade de materia seca. A producao total de frutos maduros foi 51.960 kg ha-1 ou 232 kg ha-1 dia-1 de permanencia da cultura no ambiente protegido. Os frutos comerciais corresponderam a 92,8% da producao total.

Produção e qualidade do tomate produzido em substrato, no campo e em ambiente protegido

The tomato (hybrid Carmen) fruit yield and quality in the FITO system were evaluated, using plastic bags containing organic compost + sand + nutrients, in the field and under unheated greenhouse conditions. Seven treatments were evaluated: 1) FITO, under unheated greenhouse, using perforated plastic bags, with 9 dm3 substratum per plant, containing 25% of organic compost and 75% of sand, all the macro and micronutrientes being added through trickle irrigation; 2) FITO A, similar to the previous treatment, except that only sand was used as substratum; 3) FITO 1, similar to FITO, except that the N and K were applied through trickle irrigation and the other nutrients were directly mixed in the substratum; 4) check plot in unheated greenhouse in which plants were directly transplanted in the soil; 5) FITO C, similar to FITO, except that the plants were cultivated under field condition; 6) check plot in unheated greenhouse in which plants were transplanted to the soil N and K being applied through trickle irrigation; 7) check plot with plants directly transplanted in the soil under field conditions. The experiment was conducted in randomized blocks design with four repetitions. There was no significant effect of treatments on N, Zn and Mn contents in leaf; in big and small sized fruits; in total fruit yield and fruit quality (pH, acidity, total soluble solids and vitamin C). Significant differences were found among treatments for leaf dry weight, medium, commercial and non-commercial production of fruits per day after transplantation (PCD). Significant differences were observed for P, K, Ca, Mg, S, Fe and Cu contents in leaves. The highest commercial, weighted and PCD yields, 104.79 t ha-1, 94,71 t ha-1 and 0.851 t ha-1 day-1, respectively, were obtained with the FITO system. However these values did not differ from those observed in the check plot using soil in the unheated greenhouse. FITO system can substitute the cultivation in the soil, either in the field or in unheated greenhouse.

Selection of a chitosan gelatin-based edible coating for color preservation of beef in retail display.

Chitosan gelatin-based coating films were applied to beef steaks, and their effects on color preservation and lipid oxidation during retail display were evaluated. Response surface methodology was used to model and describe the effects of different biopolymer concentrations (0 to 6% gelatin; 0.5 to 1.5% chitosan; and 0 to 12% glycerol based on dry gelatin+chitosan weight) in the coating film for optimizing the best combination for meat application. Film application reduced weight loss and lipid oxidation of the steaks after 5 days of storage, and films with higher gelatin concentrations were more effective. The percentage levels of different myoglobin-redox forms were not affected by coating, but myoglobin oxidation during retail display was reduced and the percentage of deoxymyoglobin increased with the gelatin content of the film. Steak color stability during retail display was promoted by film application; the steaks exhibited a darker, more intensely red color when coated in blends with higher gelatin and chitosan contents. Blends containing between 3% and 6% gelatin, between 0.5% and 1.0% chitosan and 6% glycerol exhibited the best results and provide a promising alternative to the preservation of beef in retail display.

Produtividade e qualidade de frutos de meloeiro variando número de frutos e de folhas por planta

The muskmelon cultivation in southeast of Brazil is possible in greenhouse but plants should be pruned. However, in this species plant growth and fruit yield are limited by both source and sink size activity. The muskmelon fruit productivity and quality in greenhouse were evaluated as affected by fruit and leaf numbers left in the plant. Split plot scheme, in a randomized blocks design, with four replications were used. The plot consisted of the fruit number per plant (1 or 2). The fruits were fixed at betweenthe 6 and 80 nodes. The split-plot consisted of the leaf number left in each plant (16; 19; 22 and 25). When the plant was pruned from the 22th leaf and one fruit/plant was left, the leaf area increased as compared with plants with two fruits. Independently of the number of leaves, plants with only one fruit presented larger mean fruit weight and smaller commercial yield. Sink reduction (fruit number/plant) provided fruits with larger net rind, pulp thickness, length, diameter, total soluble solids, total soluble sugars and no reduced sugars. On the other hand, the number of fruits/plant did not affect the titratable acidity and the reduced sugars. Except for the titratable acidity that declined and the cavity diameter of the fruit that presented quadratic answer, all the characteristics evaluated presented linear increment with the increase in the number of leaves for plant.

Produção do tomateiro em função de doses de nitrogênio e da adubação orgânica em duas épocas de cultivo

A producao de frutos de tomateiro em resposta a doses de nitrogenio e a adubacao orgânica foi avaliada em dois experimentos de campo conduzidos na primavera-verao e no outono-primavera, em 1999. Os experimentos foram instalados Universidade Federal de Vicosa, em solo da classe Argissolo Vermelho-Amarelo Câmbico. Em ambos, as doses de N aplicadas, na forma de nitrocalcio, foram 0, 110, 220, 440 e 880 kg/ha e as doses de materia orgânica, na forma de esterco bovino curtido, foram 0 e 8 t/ha. Os experimentos seguiram o delineamento em blocos ao acaso, no arranjo fatorial 5x2, com quatro repeticoes. A produtividade foi influenciada pelas doses de N, nos dois niveis de materia orgânica, nas duas epocas. No experimento de primavera-verao, as maximas producoes total, comercial e extra foram 44,78; 25,10 e 23,52 t/ha, obtidas com as doses de 530,2; 464,2 e 434,8 kg/ha de nitrogenio, respectivamente, sem adicao de materia orgânica; e 45,75; 25,87 e 24,53 t/ha, obtidas com as doses de 574,2; 513,3 e 599,8 kg/ha de nitrogenio, respectivamente, com adicao de materia orgânica. No experimento de outono-primavera, as producoes foram 99,37; 78,87 e 69,93 t/ha, obtidas com as doses de 525,4; 533,9 e 557,5 kg/ha de nitrogenio, respectivamente, sem adicao de materia orgânica; e 108,74; 87,08 e 78,09 t/ha, obtidas com as doses de 589,6; 575,3 e 557,4 kg/ha de nitrogenio, respectivamente, com adicao de materia orgânica. A adicao de materia orgânica ao solo aumentou a dose do adubo nitrogenado necessaria a obtencao das maximas producoes total, comercial e extra de frutos de tomate, em ambas as epocas de plantio.

Índice SPAD para o diagnóstico do estado de nitrogênio na cultura da abobrinha

SPAD index for nitrogen status diagnosis of zucchini plants The employment of SPAD index for N status diagnosis of crops has been largely studied in recent years. However, conclusive studies about its usefulness in zucchini plants were not found in literature. The objective of this study was to evaluate the employment of SPAD index for N status diagnosis of zucchini plants (cv. Caserta). The experiment was carried out in Vicosa, Minas Gerais State, Brazil, in a randomized block design with five rates of mineral N (0, 50, 100, 200 and 400 kg/ha), with four replications. At the early flowering stage, total chlorophyll concentration, SPAD index and total N concentration in the fourth fully expanded leaf from the apex of zucchini plants were evaluated. The total chlorophyll concentration, SPAD index and total N concentration in zucchini leaves increased following a quadratic model as a function of the N rates. The estimated critical levels of total chlorophyll concentration, SPAD index and total N concentration on zucchini leaves responsible for maximum fruit yield were 5.12 mg/g of fresh matter, 55.62 units and 3.97 dag/kg of dry matter, respectively. Significant linear and positive correlation between the evaluated characteristics was observed. The results indicate that the SPAD index can be used for N status diagnosis of zucchini plants.