Investigation of Imperata sp. as a Primary Feedstock for Compost Production in Ucayali region, Peru

Five compost piles with different initial C : N ratios have been investigated in this study. As a primary feedstock Imperata sp. was used. The primary feedstock was mixed with poultry litter and vegetable refuse in order to obtain different C : N ratio. The results show that during 64 days of well managed composting under tropical conditions the initial C : N ratio between 30:1 and 50:1 decreased to ratio 11:1 to 15:1, respectively. Results of bioassay tests expressed as the germination index (GI) indicate particular compost phytotoxicity. The value of GI was 51.4%, 48.6%, 47.8%, 46.7% and 40.0% for samples from the compost with initial C : N ratios of 30:1, 37:1, 40:1, 44:1 and 50:1, respectively

Using a Double-pass solar drier for drying of bamboo shoots

Three different drying methods, a forced convection double-pass solar drier (DPSD), typical cabinet type natural convection solar drier (CD) and traditional open-sun drying (OSD) were used for draying of bamboo shoots in central Vietnam. During drying the operational parameters such as drying temperature, relative humidity, air velocity, insolation and water evaporation have been recorded hourly. The mean drying temperatures and relative humidity in the drying chamber were 55.2°C, 23.7%; 47.5°C, 37,6%; 36.2°C, 47.8% in DPSD, CD and OSD, respectively. The mean global radiation during all experimental runs was 670 Wm−2. The result also shows that fastest drying process was occurred in DPSD where the falling-rate period was achieved after 7 hours, in change to OSD where it took 16 hours. The overall drying efficiency was 23.11%, 15.83% and 9.73% in case of DPSD, CD and OSD, respectively. Although the construction cost of DPSD was significantly higher than in CD, the drying costs per one kilogram of bamboo shoots were by 42.8% lower in case of DPSD as compared to CD. Double-pass solar drier was found to be technically and economically suitable for drying of bamboo shoots under the specific conditions in central Vietnam and in all cases, the use of this drier led to considerable reduction in drying time in comparison to traditional open-sun drying

Clean Foods: The Inhibitory Effect of Five Natural Juices on the Browning of Apple Slices during Drying

Enzymatic browning, which accompanies food preservation processes based on drying, is a common obstacle to obtaining marketable and consumer-appealing products. In this paper, we investigate the application of one of the methods commonly used in order to counter the browning process, namely dipping. Dipping involves a soaking of the foods in liquids or solutions in order to suppress the activity of polyphenoloxidase (PPO) enzymes, either by physically preventing oxygen from interacting with it, or by dramatically decreasing water activity and thus slowing down water-dependent reactions. In this study, juices from selected fresh fruits with high ascorbic acid content were used as natural preservatives with antibrowning effects. The juices were prepared from fruit of the following species: Sorbus aucuparia, Diospyros kaki, Hippophae rhamnoides, Actinidia deliciosa, and Rosa canina. The effect of selected juices on color change was tested on dried “Idared” apple slices and was compared to slices of freshly cut apples (standard). The browning index of all sample groups showed significant differences between treatment groups and the standard except for samples treated with Rosa canina juice. The effect of the juices was also evaluated via a sensory panel, where color change, degree of browning, change of taste, and overall acceptability of the resulting color and taste were evaluated. Results showed that the best antibrowning effect was achieved by macerate from fruits of Rosa canina. The results of this study showed that dipping in some plant juices has the potential of complementing or replacing the sulphite-based approach, which is the current method of choice of the food industry

Solar Drying and Sensory Attributes of Eland (Taurotragus oryx) Jerky

A double-pass solar drier (DPSD) and a laboratory oven (LO) were used for thin-layer drying of eland and beef. Prior to drying, the physicochemical characteristics of the raw meat were determined, such as pH, dry matter content (%), Warner-Bratzler shear force (N), pigment concentration (mg·kg−1), weight loss during cooking (%), water holding capacity (%), colour (L, a, b), and crude fat content (%). Both meats were pretreated with traditional jerky marinade (TM), TM with fresh pineapple juice (TMP), TM with honey (TMH), and TM with Coca Cola© (TMCCL) and compared to an untreated control (C). The sensory properties of the eland and beef jerky were assessed in a two-stage process. The surface colour values of the jerky samples were measured in the CIE L* a* b* colour space and the effect of the different pretreatments on the overall combined colour (dE) was calculated. Significant differences (p < 0.05) between raw eland and beef samples were found in case of pH, pigment concentration, water holding capacity, crude fat content, and colour (L and b). Jerky from TMP pretreated meat had the highest scores for texture, colour, and taste. Generally, for both meats dried in both driers, TMH marinade was evaluated as the one with the highest total difference dE compared to meat dipped in TMP pretreatment, which had the lowest total difference dE

Factors Associated with Household Food Security in Zambia

Food security is a global challenge and threatens mainly smallholder farmers in developing countries. The main aim of this paper is to determine factors that are associated with food security in Zambia. This study utilizes the household questionnaire survey dataset of 400 smallholder farmers in four districts conducted in southern Zambia in 2016. To measure food security, the study employs two food security indicators, namely the food consumption score (FCS) and the household hunger scale (HHS). Two ordered probit models are estimated with the dependent variables FCS and HHS. Both the FCS and HHS models’ findings reveal that higher education levels of household head, increasing livestock income, secure land tenure, increasing land size, and group membership increase the probability of household food and nutrition security. The results imply that policies supporting livestock development programs such as training of farmers in animal husbandry, as well as policies increasing land tenure security and empowerment of farmers groups, have the potential to enhance household food and nutrition security

Use of the Amazonian tree species Inga edulis for soil regeneration and weed control

Land for agriculture in the tropics is often cleared through slash and burn, which is a shifting cultivation system. However, shortening of fallow periods led to soil degradation, decreased yields and increased weed pressure. Our objective was to evaluate the effects of short-term tree fallow of Inga edulis on weeds and soil fertility. We compared four treatments, namely, (1) natural fallow, (2) planted fallow with I. Midis, (3) planted fallow with I. edulis herbaceous cover crop kudzu (Pueraria phaseoloides) and (4) continuous cropping of cassava (Manihol esculenta). Tree and weed biomass amount and composition were determined at 3, 6, 9, 13, 17, 20, 24, 28 and 33 months after establishment, while soil samples at 17 and 25 months. The growth rate of I. edulis was slow when compared with other studies. However, improved fallows were able to significantly decrease aboveground weed biomass. Total biomass of improved fallows increased more rapidly than that of natural fallow and cassava cropping. There were no significant soil fertility differences between treatments and all fallows increased the organic matter in topsoil over time. Available P declined in all treatments but stocks of aboveground N, P and K increased more rapidly under improved fallows. Planted fallows using trees such as I. Mulls have the potential to reduce growth of weed species and improve some soil fertility parameters but, on highly degraded soil, a longer time and possibly P fertilisation may be needed to achieve these increases

Agent Orange Footprint Still Visible in Rural Areas of Central Vietnam

Levels of polychlorinated dioxins/furans (PCDD/PCDF) in selected environmental samples (soils, sediments, fish, and farm animals) were analyzed from the area of Phong My commune (Thua Thien-Hue province, Vietnam). This area was affected by Agent Orange spraying during the Vietnam war (1968–1971). Whereas PCDD/PCDF content in soil and sediment samples is relatively low and ranges between 0.05 and 5.1 pg WHO-TEQ/g for soils and between 0.7 and 6.4 pg WHO-TEQ/g for sediments, the PCDD/PCDF content in poultry muscle and liver in most cases exceeded the maximum permissible limit of dioxin content per unit fat mass. In some cases of soil and sediments samples, 2,3,7,8-TCDD represented more than 90% of the total PCDD/PCDF, which indicates Agent Orange as the main source

Methods for short-term control of Imperata grass in Peruvian Amazon

The traditional control of Imperata brasiliensis grasslands used by farmers in the Peruvian Amazon is to burn the grass. The objective of this study was to compare different methods of short-term control. Biological, mechanical, chemical and traditional methods of control were compared. Herbicide spraying and manual weeding have shown to be very effective in reducing above-and below-ground biomass growth in the first 45 days after slashing the grass, with effects persisting in the longer term, but both are expensive methods. Shading seems to be less effective in the short-term, whereas it influences the Imperata growth in the longer term. After one year shading, glyphosate application and weeding significantly reduced aboveground biomass by 94, 67 and 53%; and below ground biomass by 76, 65 and 58%, respectively, compared to control. We also found a significant decrease of Imperata rhizomes in soil during time under shading. Burning has proved to have no significant effect on Imperata growth. The use of shade trees in a kind of agroforestry system could be a suitable method for small farmers to control Imperata grasslands

Development of Solar Drying Model for Selected Cambodian Fish Species

A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R2), chi-square (χ2) test, and root-mean-square error (RMSE), the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing