Engineering in Agriculture, Environment and Food最新文献

The main fluorescent compounds in Japanese dace fish (Tribolodon hakonensis) eye fluid associated with freshness were distinguished and their time-dependent changes with storage were observed. For this experiment 95 fish were stored at 20 °C for 36 h, meat from the dorsal part was sampled at different storage times and used to measure K value, a standard freshness index. At the same time eye fluid was collected from the fish for fluorescence spectra acquisition and biochemical analysis. K value results showed the fish remained fresh up until 18 h of storage, and then deteriorated quickly thereafter. While aromatic proteins and amino acids were confirmed to be the main fluorescent compounds in eye fluid, they showed a complicated change during storage. Fluorescent compounds of uric acid, closely associated with freshness, had low intensity values at the start of storage, with values raising sharply later in storage; showing an exponential increase during storage. Dityrosine was found to be present only at a very late stage of storage. These results indicate the connection between specific fluorescent compound changes and the progression of storage could be employed as a meaningful predictor of fish freshness.

Polyhydroxybutyrate (PHB), a biodegradable polymer (an intracellular product) was produced using Bacillus safensis EBT1. A kinetic model that describes microbial growth, biopolymer production and substrate consumption was used to predict the performance of batch fermentation of Bacillus safensis EBT1. The experimental data were fitted with modified logistic equation. The specific growth rate (μ_max) and half saturation constant (K_s) values for the models such as Monod, Contois and Herbert were found to be 0.16, 0.15, 0.13 h⁻¹ and 79.51, 68.19, 43.39 g/L respectively. Leudeking-Piret kinetics indicated that PHB formation in this study as growth associated. The recovered polymer was characterized using Transmission Electron Microscopy, Differential Scanning Calorimetry, Thermogravimetry analysis and Nuclear Magnetic Resonance. The PHB produced was used to synthesize nanoparticles using modified nano-precipitation method.

Wastes from Merluccius hubbsi processing were used for biological silage elaborated with Lactobacillus arizonensis and for chemical silage performed with 0.18M sulfuric acid and 0.22M formic acid. Mice BALB/c were fed with isoenergetic diets, EFBS and EFCS, containing 36.3% (wt/wt) biological fish silage and 36.3% (wt/wt) chemical fish silage respectively. Promisingly, after 30 day consumption both additives did not provoke lesions in the gut, thinner wall, distension or abnormal vascularization. The higher concentration of lactic acid bacteria (LAB) in the gut of mice fed with EFBS (2.51 × 10⁴ cfu LAB/g EFBS vs. 3.98 × 10³ cfu LAB/g EFCS), together with the weight gain (23.8 ± 3.8 g vs. 16.7 ± 3.7 g), feed conversion ratio (4.12 vs. 6.71), protein efficiency rate (0.69 vs. 0.63), villi height (455 μm vs. 418 μm) for EFBS and EFCS respectively, support the probiotic effect of L. arizonensis. Nevertheless, both preparations are interesting options to envisage a promising outcome for recycling fish wastes.

This paper studies the energy consumption and finding relationship between energy inputs and yield, per hectare production of melon farms in Khorasan Razavi province, Iran. To this end, the data were collected from 94 farmers which were selected based on random sampling method. Total energy inputs in all stages of melon production was estimated as 1069332.26 MJ ha⁻¹. Fuel (81.79%) was the most contributor to the energy consumption followed by Farmyard manure (13.34%). Energy use efficiency and energy productivity were gained 0.18 and 0.23 kg MJ⁻¹, respectively. 84.95% of the total energy input was non-renewable while 15.05% was renewable. The shares of direct and indirect energy inputs were 83.03% and 16.97%. Econometric estimation results revealed that diesel fuel (0.90) had the highest impact among the inputs in melon production. The contribution of machinery, fertilizers, farmyard manure and water for irrigation was significant at the 1% level.

Design

optimization and online evaluation of work quality of tillage tools help to find optimal balance between effort and result in tillage operation. Currently, usage of laser scanner has become widespread to examine the soil profile after tillage. However, the results are significantly affected by external circumstances in the field such as sunlight, weeds, residual of plant, etc. Therefore, a soil bin test was carried out by using a laser scanner to evaluate the width and the area of the furrow (shape of furrow) created by using four standard chisel plow tines heavy duty, double heart, double heart with wing and duck foot with widths of cut 0.065, 0.135, 0.450, and 0.400 m, respectively at different speeds and depths. MATLAB based computer program was used to estimate soil profile parameters. Lab results were verified in a field test. The field results were evaluated based on geometric shape of the furrow obtained from the soil bin and a model based on Willatt and Willis's approach in predicting the furrow shape. Results show that the width of the furrow increases linearly with depth while the area of the furrow increases quadratically with depth for all tines. An excellent geometric shape of the furrow was obtained from the soil bin for every tine. The furrow shape is triangle for heavy duty and double heart tines, while it is triangle plus trapezoidal shape for double heart with wings and duck foot tines. Willatt and Willis's equation related to the width of the furrow shows a good agreement for heavy duty and double heart tines at shallow depth.

A mechanical mulching of soils during planting seedlings is becoming popular due to the shortage of labor. Evaluation of the dual action equipment for mulching soils along with planting of vegetable seedlings has been undertaken for qualitative performance of operations and productivity. The device was evaluated in production conditions for receiving its operational indicators. The deviation from a longitudinal axis line of planting seedlings was 5 cm and depth of planting seedling was 12 cm. The average field capacity of the combined machine in planting seedlings of vegetables was about 0.405 ha/hr. The average forward speed of machine was 2.03 km/h and thus average quantity of the planted seedlings was 271 seedlings/min.

The aim of this study was to determine the appropriate strategy for cattle manure composting with forced aeration. The composting of cattle manure was conducted using an 18.8 L reactor with three different amounts of total air supplied (1080, 3240 and 10,800 L/kg dry mass) during 360 h of composting using continuous and on/off sequencing (20 min/h) aeration methods and three turning patterns (no turning, full turning and turning with position change). The degradation of organic matter in three-stage systems (the compost was turned every 120 h over the 360 h period) was significantly affected by total air supply volume and was large in the case of on/off sequence aeration. The pattern of moisture change was more affected by turning than by aeration modes. The optimal composting conditions for organic matter degradation (maximum of 37.7%) were aeration rate: 0.45 L/min kg dm, aeration mode: on/off sequencing process and full turning. The total accumulated weight losses and heat generated during composting indicated significant effects of the total air supplied and were large in the case of the continuous process.

Bee-pollen is an important source of nutritional and bioactive compounds. Given its high moisture content, bee-pollen is dried before commercialization; however, there are some drawbacks in the microbiological quality, which have a remarkable effect on the physicochemical stability. The aim of this study was to evaluate the influence of drying on bee-pollen at temperatures between 40 °C and 60 °C based on microbiological, structural and physical-chemical characteristics. The obtained results showed that bee-pollen dried at 40 and 50 °C had a significant increase in acidity after treatment, possibly due to the remain microbiological load. In contrast, a significant increase in flavonoids, phenolics and antioxidant activity was found for all thermal treatments; nonetheless, a loss of carotenoids by the effect of temperature was also obtained. Microscopy images showed a slight degradation in the bee-pollen structure, which may have caused the release of bioactive compounds, increasing the antioxidant capacity. A total ranking technique suggested the most adequate temperature for drying bee-pollen at 60 °C.

In this study, X-ray computed tomography (CT) was used as a non-destructive technique to characterize and quantify the internal structure of cucumber fruit during storage. The physical properties of cucumber fruit were also measured destructively and related to X-ray absorptivity, and also changes in three-dimensional heterogeneous internal structure were visualized during storage at 15 °C and 25 °C and 90% RH for 7 days. As a result, the average gray scale (GS) value calculated from X-ray CT scanned tissue images indicated good correlations with the density, porosity, and elastic modulus of cucumber fruit. The peak height of the GS value related to the density and porosity. Standard deviation of the GS value was also related to the moisture content of the fruit. These results indicated that X-ray CT can be used to estimate physical properties related fruit quality. It was also revealed that the radiodensity of cucumber fruit changed in the mesocarp tissue but not change in the placenta tissue. GS level in the mesocarp tissue changed from white to dark from the fruit pedicel towards the apex at 25 °C. This result is useful to understand the expansion of low density part in fruit during storage.

In China, the crop diseases and insect pests are the main causes of output reduction and quality decline of crops. Through inspection of crop insects, we can prevent the pests in a timely and effective manner. The visible-near infrared (VNIR) spectral reflectance can intuitively reflect the growth, disease and insect pests information of crops, and through analysis of the crop's reflectance spectrum, we can detect and identify the crop pests. Clustering analysis is an important multivariable statistic and analysis method, and with the unsupervised learning method, we can effectively detect and classify the spectra of crop pests. In this paper, by using the spectral acquisition device designed by us, we collected three types of pests spectra on fresh broad bean leaves in a laboratory environment. We propose a scheme to analyze the clustering performance of crop pests spectra with the K-Means and the FCM clustering methods, and Matlab 2012b was used to realize the two clustering algorithms and analyze these clustering results. The experiment results show that the FCM clustering method has a better rate of identification, while the K-means clustering method has higher execution efficiency.