RESUMEN
The Hass cultivar is one of the most cultivated and distributed avocado varieties throughout the world, having high productivity, nutritional quality, market acceptance and adaptation to different climatic zones (Dreher and Davenport 2013). Anthracnose affects avocado production in tropical and subtropical regions, causing economic losses, especially post-harvest (Fuentes-Aragón et al. 2020). Correct identification of Colletotrichum species causing anthracnose is essential, as different species vary in important phenotypes such as virulence and sensitivity to fungicides (Chen et al. 2016). Twelve samples from batches of avocados with anthracnose were collected in Minas Gerais State, Brazil, in September 2023. The observed symptoms were brown to black depressed circular spots, ranging from a few millimeters to 3 cm in diameter on the epicarp of the fruits, covered in center by mucilaginous layers of pathogen sporulation. Isolation was performed directly from the spore masses and monoconidial isolates were cultured in PDA at 25°C for 7 days for morphological characterization and preserved in sterile water at 4°C. One of the morphotypes commonly recovered from lesions, represented by isolate UCBV 362 (Culture Collection COAD 3843), formed fast-growing colonies having white aerial mycelium and intense salmon-colored sporulation. The cylindrical conidia were 13 to 17.5 µm long and 4.5 to 7 µm wide (average 14.5 x 5.7 µm, N=100), produced on conidiophores dispersed in the aerial mycelium or aggregated on melanized conidiomata formed on the agar. The partial sequence of the second largest subunit of the RNA polymerase II gene (RPB2) from isolate UCBV 362 (GenBank: PQ034617, 1116 nt) showed 99% of coverage and 99.37% of nucleotide identity with the RPB2 sequence of the ex-epitype strain of Colletotrichum nymphaeae ICMP 17918 (=CBS 515.78) (GenBank: JN985506). In a Maximum Likelihood phylogenetic tree composed with RBP2 sequences from reference strains of the Colletotrichum acutatum species complex, the isolate UCBV 362 formed a highly supported clade with the ex-epitype and other reference strains of Colletotrichum nymphaeae, occupying the Clade 2 of the species complex together with C. scovillae and C. simmondsii (Damm et al. 2012). This result shows the reliability of RPB2 for phylogeny and species delimitation within Colletotrichum. To confirm pathogenicity, 10-mm discs from a 7-day-old colony were inoculated at 3 different points on healthy-looking avocado fruits and incubated at 28°C. Uninoculated fruits served as controls. The first symptoms appeared 5 days after inoculation and were similar to those observed in the original samples, while the fruits in the control group remained asymptomatic. The pathogen was reisolated from the lesions and identified morphologically, fulfilling Koch's postulates. Colletotrichum nymphaeae has been associated with avocado anthracnose in Mexico (Fuentes-Aragón et al. 2020). In Brazil, a study based on molecular phylogeny identified Colletotrichum siamense and C. karsti as etiological agents of this disease (Soares et al. 2021). This report expands the range of species that cause avocado anthracnose in Brazil and provides etiological information for the implementation and monitoring of control methods, especially chemical control.
RESUMEN
Proteins are the most abundant macromolecules in living cells and their primary role in the diet is to supply the body with essential amino acids in adequate quantities for the synthesis and maintenance of body tissues. The determination of protein digestibility of foods is an important factor to estimate their quality and the in vitro methodology is a fast and easy way to perform it. This study aimed to determine the influence of lipids on the in vitro digestibility of animal and vegetable proteins. The following protein sources: oat, beef, chicken, fish and pork meats, red beans, milk powder, textured soy protein (TSP), quinoa and five soybean varieties were evaluated. Animal proteins presented higher in vitro values than vegetable proteins, except for the textured soy protein, which presented higher digestibility based on the thermal treatment. In this study, there was no statistic difference between lipid content and protein digestibility. Therefore, there is no need that samples be defatted prior the analysis of the in vitro digestibility, using an enzymatic system containing the enzymes trypsin and pancreatin, which facilitates even more the use of these methods for foods with high lipid levels in food industries.
As proteínas são as macromoléculas mais abundantes nas células vivas, tendo como principal função na dieta suprir o organismo de aminoácidos indispensáveis em quantidades adequadas para síntese e manutenção dos tecidos corporais. Desse modo, a determinação da digestibilidade proteica de um alimento é um fator importante para estimar a sua qualidade, sendo o método in vitro uma alternativa rápida e fácil. Neste trabalho, objetivou-se determinar a influência dos lipídios na digestibilidade in vitro de proteínas de origem animal e vegetal. Foram utilizadas as seguintes fontes de proteína: aveia, carnes: bovina, de frango, de peixe e suína, feijão vermelho, leite em pó, proteína texturizada de soja (PTS), quinoa e cinco variedades de soja. As proteínas de origem animal apresentaram maiores valores de digestibilidade in vitro que as de origem vegetal, exceto a proteína texturizada de soja que apresentou maior digestibilidade, em razão do processamento a que foi submetido. No presente trabalho, não houve diferença estatística entre diferentes conteúdos de lipídios sobre a digestibilidade proteica. Desse modo, sugere-se não ser preciso desengordurar as amostras antes de analisar a digestibilidade in vitro, usando o sistema enzimático contendo as enzimas trispisna e pacreatina, tornando-se ainda mais fácil a utilização desses métodos para alimentos com alto teor de lipídio em indústrias de alimentos.
RESUMEN
Este trabalho objetivou estudar o enriquecimento de leite em pó com duas fontes diferentes de ferro: sulfato ferroso e ferro aminoácido quelato. As fontes de ferro foram adicionadas antes e após a secagem do leite. Foram estadadas a reconstituição, a estabilidade oxidativa e a biodisponibilidade das fontes de ferro. Quanto à forma de enriquecimento não houve diferença entre as características estudadas. Ambos os processos tecnológicos mostraram-se simples e de fácil execução em laboratório. A estabilidade oxidativa do leite enriquecido foi maior quando se utilizou ferro aminoácido quelato e ambas as fontes apresentou mior biodisponibilidade in vitro (31,81 por cento) que o sulfato ferroso (17,41 por cento). A biodisponibilidade in vivo, deduzida, foi de 15,45 por cento para o ferro aminoácido quelato e de 8,66 por cento para o sulfato ferroso. O ferro aminoácido quelato mostrou melhor estabilidade oxidativa e melhor biodisponibilidade comparado com o sulfato ferroso, constituindo boa fonte para o enriquecimento do leite em pó.