Effect of orange juice's processing on the color, particle size, and bioaccessibility of carotenoids

This study was aimed at assessing the differences between industrially processed and hand-squeezed orange juices (OJs) in relation to their color, particle size, carotenoid content, and carotenoid bioaccessibility. Specifically, industrial samples of fresh squeezed OJs after the finishing steps (FISO) and the same OJs after pasteurization (PISO), as well as hand-squeezed OJs (HSO) were studied. The results showed that the HSO and PISO were different (p < 0.05) in terms of color (darker and more reddish vs brighter, more yellowish and colorful), particle size (volume and surface area mean diameter), and total carotenoid content (29 ± 5 and 22 ± 3 mg/L, respectively). On the other hand, the industrial extraction of OJs reduced the particle size distribution, and accordingly, the relative bioaccessibility of bioactive carotenoids increased (p < 0.01). Independently of the type of OJ, the bioaccessibility of carotenoids in decreasing order was the following: α-carotene > β-cryptoxanthin > β-carotene > zeaxanthin > lutein.     

Analysis of soil fertility and its anomalies using an objective model

In this work, the use of an objective method, the formulation of the Rasch measurement model, which synthesizes data with different units into a uniform analytical framework, is considered to get representative measures of soil fertility potential in an experimental field. Thus, two types of information about the soil were obtained from soil samples taken at 70 locations: first, the textural components were determined, and, secondly, deep (ECa‐90) and shallow (ECa‐30) soil apparent electrical conductivity, approximately 0–90 and 0–30 cm depths, respectively, were measured. A latent variable, denominated soil fertility potential, was defined. It is supposed, and later it is verified, that all soil properties previously indicated have a marked influence on the latent variable. The adequate assignment of categorical values across properties measures and the good fit of the data are checked as a previous phase to properly compute the Rasch measures. After applying the Rasch methodology, it was obtained that both electrical conductivities are the most influential properties on soil fertility potential, getting moreover a ranking of all soil samples according to their fertility potential and the unexpected behaviors, called misfits, of some soil samples, which constitute a very useful information to better match soil and crop requirements as they vary in the field, being a rational basis for a site‐specific crop management.     

Nitrogen‐use efficiency of young citrus trees as influenced by the timing of fertilizer application

The aim of this study was to improve the fertilizer‐nitrogen‐use efficiency (NUE) for a sustainable citrus production where yield, fruit quality, and environment are reconciled. A soil pot experiment was conducted using 5‐year‐old orange trees (Citrus sinensis cv. Navel Lane Late) to determine the response of NUE to timing of N‐fertilizer supply. An equal N rate (50 g tree^–1) following two seasonal supply distributions was tested: (1) ENS (early supply from March to June of 75% of the N rate, with the remaining 25% administered between July and October) and (2) LNS (late supply of the bulk of the N rate with 25% between March and June and 75% between July and October). Labeled fertilizer (5 atom% ¹⁵N excess) was applied in order to accurately quantify N uptake, its partitioning among plant–soil compartments and NUE at the end of fruit drop and at fruit maturity. LNS resulted in a significant increase in NUE in both stages (up to 19% at the end of fruit drop and 9% at fruit maturity), while also increasing summer/autumn flush development. ENS showed lower fruit abscission, an enhanced final fruit load (up to 45%), and a more profuse development of spring flush. It is worth mentioning that LNS led to higher ¹⁵N content in the majority of the tree storage organs available for next spring growth resumption. The amount of ¹⁵N remaining in the soil of ENS trees at the end of the trial, which represented 16% of the supplied ¹⁵N, was 1.5‐fold higher than that of LNS trees as a result of the lower NUE of the former. Irrespective of the seasonal distribution of the fertilizer, mean ¹⁵N recovery in the soil–plant system at the end of the trial was about 71%. The results clearly confirm that the N seasonal distribution curve affects NUE in young citrus trees and NUE increases when the bulk of supply of the N rate is delayed to the summer months.     

Antimutagenic Properties of Mangifera indica L. Stem Bark Extract and Evaluation of its Effects on Hepatic CYP1A1

Mangifera indica stem bark extract (MSBE) is a Cuban natural product which has shown strong antioxidant properties. In this work, the antimutagenic effect of MSBE was tested against 10 well-known mutagens/carcinogens in the Ames test in the absence or presence of metabolic fraction (S9). The chemical mutagens tested included: cyclophosphamide, mitomycin C, bleomycin, cisplatin, dimethylnitrosamine (DMNA), benzo[a]pyrene (BP), 2-acetylaminofluorene (2-AAF), sodium azide, 1-nitropyrene (1-NP) and picrolonic acid. Protective effects of the extract were also evaluated by comparing the efficiency of S9 fraction obtained from rats treated during 28?days with oral doses of MSBE (50?C500?mg/kg) with that obtained from rats treated with vehicle (control) to activate bleomycin and cyclophosphamide in the Ames test. MSBE concentrations between 50 and 500???g/plate significantly reduced the mutagenicity mediated by all the chemicals tested with the exception of sodium azide. Higher mutagenicity was found when bleomycin and cyclophosphamide (CP) were activated by control S9 than by MSBE S9. In addition, inhibition of CYP1A1 microsomal activity was observed in the presence of MSBE (10?C20???g/ml). We can conclude that besides its potent antioxidant activity previously reported, MSBE may also exert a chemoprotective effect due to its capacity to inhibit CYP activity.     

Antibacterial activity of plant extracts obtained with alternative organics solvents against food-borne pathogen bacteria

The objectives of this study were: the chemical characterization of extracts from seven plants (Larrea tridentata, Flourensia cernua, Lippia graveolens, Agave lechuguilla, Yucca filifera, Opuntia ficus-indica, and Carya illinoensis) which are acclimated to the Mexican semi-desert. The extracts were obtained using Soxhlet method by water, ethanol and an infusion method using alternative organic solvents (lanolin and cocoa butter), in addition it was evaluated the antibacterial activity of semi-desert plant extracts against Enterobacter aerogenes, Escherichia coli, Salmonella typhi and Staphylococcus aureus. Chemical characterization of plant extracts showed that they are rich in secondary metabolites; cocoa butter was the non-conventional solvent which it was possible to obtain the highest content of total tannins. It was not possible to identify saponins in those extracts where non conventional solvents were used. While in extract where non conventional solvents were used, it was only possible to detect the presence of terpenes in creosote bush and prickly pear extracts. S. aureus was the bacterial strain that showed the highest growth inhibition as consequence of the plant extracts. The use of semi-desert plant extracts obtained using organic solvents are a good alternative for food-borne pathogen bacteria control because all the bacterial growth decreased with the tested extracts.     

Effect of dietary protein level and source on digestive proteolytic enzyme activity in juvenile Senegalese sole, Solea senegalensis Kaup 1850

The effect of dietary protein level and protein source on growth and proteolytic activity of juvenile Solea senegalensis was studied. In Experiment 1, fish were fed on four experimental diets containing increased protein levels (36, 46, 56 and 67%). In Experiment 2, Senegalese soles were fed on five diets with partial substitution of fish meal by soybean meal, soybean protein concentrate, soybean protein isolate, wheat gluten meal or pea protein concentrate. Results prove that growth and proteolytic activity in the distal intestine of fish were affected by the quantitative increase in dietary protein. The origin of protein source used in the elaboration of experimental diets affected both the amount and composition of the alkaline proteases secreted into the intestinal lumen; however, it did not decrease animal growth. Juvenile Senegalese sole showed capability to modulate digestive protease secretion when the concentration and/or source of dietary protein were modified. Quantity and quality of dietary protein affected protein hydrolysis in Senegalese sole intestine. This study establishes that 30% fish meal protein can be replaced by soybean derivatives without affecting intestinal proteases. Replacement with wheat gluten meal or pea protein concentrate should be taken cautiously, but further research is needed to establish whether growth performance and digestive enzyme physiology of Senegalese sole are affected by plant protein-supplemented diets in a long-term trial.     

Application of artificial photoperiod in fish: a factor that increases susceptibility to infectious diseases?

This paper describes and evaluates the mortality associated with the potential stressor effect induced by application of artificial photoperiods in rainbow trout (Oncorhynchus mykiss). After application of artificial photoperiods, high mortalities of trout subjected to this management were recorded (36% in LD 14:10 and 25% in LD 24:0) as compared to controls (7%). The recorded signology related to diseased trout included darkening, lethargy and erratic swimming. Among the morphological changes, skin lesions and ulcerative-type necrosis could be observed. Blood tests, histopathology and isolation of pathogens identified as Flavobacterium psychrophilum, associated with Aeromonas, Pseudomonas and Saprolegnia sp., were performed. The application of artificial photoperiods suggests that fish may be more susceptible to opportunistic diseases; thus, it is advisable to emphasize preventive measures in fish subjected to this management.     

RaGPS: A software application for determining extraterrestrial radiation in mobile devices with GPS

The application of mobile devices to the food and agriculture sector has been increased notably in the last years, being most of these devices endowed with Global Positioning System by satellites (GPS). This paper presents a new software application developed with LabVIEW for determining extraterrestrial solar radiation, equivalent evaporation and other parameters related to solar position from Global Position Data in handheld devices. These parameters are useful in many applications, such as validating the data supplied by agricultural weather stations, estimating the water needs of the crops where there are no close weather stations, or providing essential information when considering a determined place for installing photovoltaic panels or solar water heating systems. There is currently no software in the market which confers this utility to a mobile device. A comparison between data calculated by the proposed application and data supplied by an agricultural weather station was carried out for evaluation and validation purposes.     

Strength attributes and compaction susceptibility of Brazilian Latosols

In this study, strength attributes and compaction susceptibility of the main classes of Brazilian Latosols (Oxisols), under native vegetation, were studied using the load bearing capacity models relating precompression stress, compression index and water potential through statistical regression models. These models were developed based on the results of the analysis of undisturbed soil samples collected at the B horizon at the different sites. The results showed that the maximum value of the compression index was 0.53 for the Acric Red Latosol, indicating its higher susceptibility to soil compaction. The Dystrocohesive Yellow Latosol had the highest load bearing capacity, while the Acric Red Latosol had the lowest one. The Dystrocohesive Yellow Latosol due to its high load bearing capacity and bulk density (mechanical resistance) behave similarly to hardsetting soil, in which the plants root system has severe physical restrictions to explore deeper horizons during the dry periods. Differences in the load bearing capacity and compaction susceptibility were found to be influenced by soil structure which is associated with clay mineralogy in these very weathered-leached soils and water potential. The study also showed that soil compression index is influenced by water potential and clay mineralogy also. Our work has laid a foundation for estimation of compaction susceptibility of Latosols.