Application of Visible to Near-Infrared Spectroscopy for Non-Destructive Assessment of Quality Parameters of Fruit

The accuracy and robustness of prediction models are very important to the successful commercial application of visible to near-infrared spectroscopy (Vis-NIRS) on fruit. The difference in physiological characteristics of fruit is very wide, which necessitates variance in the type of spectrometers applied to collect spectral data, pre-processing of the collected data and chemometric techniques used to develop robust models. Relevant practices of data collection, processing and the development of models are a challenge because of the required knowledge of fruit physiology in addition to the Vis-NIRS expertise of a researcher. This chapter deals with the application of Vis-NIRS on fruit by discussing commonly used spectrometers, data chemometric treatment and common models developed for assessing quality of specific types of fruit. The chapter intends to create an overview of commonly used techniques for guiding general users of these techniques. Current status, gaps and future perspectives of the application of Vis-NIRS on fruit are also discussed for challenging researchers who are experts in this research field

Mechanism of enhanced freshness formulation in optimizing antioxidant retention of gold kiwifruit (Actinidia chinensis) harvested at two maturity stages

Kiwifruit exhibits a climacteric ripening pattern and has as an extremely perishable nature. Considering that high perishability leads to a loss in antioxidants and overall nutritional quality. This study aimed to examine the efficacy of enhanced freshness formulation (EFF), a hexanal-based formulation containing antioxidants such as geraniol, α-tocopherol and ascorbic acid, on maintaining the bioactive compounds of gold kiwifruit (cv. ‘Y368’) harvested at two maturity stages. Kiwifruits were treated with three treatments, namely, control (untreated fruit), 0.01 and 0.02% (v/v) EFF. Fruits were treated with 8 weeks of cold storage at 0°C and 90% relative humidity, then transferred to 20°C for 8 days. Three bioactive compounds (ascorbic acid, total phenolics and flavonoids), antioxidant capacities using DPPH and FRAP assays, polyphenol oxidase, ascorbate oxidase, phenylalanine and tyrosine ammonia lyase enzyme activities were evaluated. The results showed that EFF significantly (p < 0.05) influenced bioactive compounds, antioxidant capacities and the activity of enzymes involved in the synthesis and oxidation of bioactive compounds. The maturity stage significantly influenced the content of bioactive compounds. Later harvested kiwifruit had greater content of bioactive compounds, compared to earlier harvested kiwifruit. The total phenolic content was 0.77, 1.09 and 1.22 mg GAE g−1 FW for control, 0.01 and 0.02% EFF, respectively. The FRAP antioxidant concentration was 0.76, 0.91 and 0.96 μmol Fe (II) g−1 FW for control, 0.01 and 0.02% EFF. The findings illustrate the capacity of EFF to optimize bioactive compounds and storability of kiwifruit during postharvest storage

Prediction of ‘Nules Clementine’ mandarin susceptibility to rind breakdown disorder using Vis/NIR spectroscopy

The use of diffuse reflectance visible and near infrared (Vis/NIR) spectroscopy was explored as a non-destructive technique to predict ‘Nules Clementine’ mandarin fruit susceptibility to rind breakdown (RBD) disorder by detecting rind physico-chemical properties of 80 intact fruit harvested from different canopy positions. Vis/NIR spectra were obtained using a LabSpec® spectrophotometer. Reference physico-chemical data of the fruit were obtained after 8 weeks of storage at 8 °C using conventional methods and included RBD, hue angle, colour index, mass loss, rind dry matter, as well as carbohydrates (sucrose, glucose, fructose, total carbohydrates), and total phenolic acid concentrations. Principal component analysis (PCA) was applied to analyse spectral data to identify clusters in the PCA score plots and outliers. Partial least squares (PLS) regression was applied to spectral data after PCA to develop prediction models for each quality attribute. The spectra were subjected to a test set validation by dividing the data into calibration (n = 48) and test validation (n = 32) sets. An extra set of 40 fruit harvested from a different part of the orchard was used for external validation. PLS-discriminant analysis (PLS-DA) models were developed to sort fruit based on canopy position and RBD susceptibility. Fruit position within the canopy had a significant influence on rind biochemical properties. Outside fruit had higher rind carbohydrates, phenolic acids and dry matter content and lower RBD index than inside fruit. The data distribution in the PCA and PLS-DA models displayed four clusters that could easily be identified. These clusters allowed distinction between fruit from different preharvest treatments. NIR calibration and validation results demonstrated that colour index, dry matter, total carbohydrates and mass loss were predicted with significant accuracy, with residual predictive deviation (RPD) for prediction of 3.83, 3.58, 3.15 and 2.61, respectively. The good correlation between spectral information and carbohydrate content demonstrated the potential of Vis/NIR as a non-destructive tool to predict fruit susceptibility to RBD

Bottle Gourd Landraces and Its Potential Contribution to Food Security

Issues surrounding water scarcity and malnutrition in the rural household of sub-Saharan Africa continue to be a problem and pose threat to food security. In such cases, traditional and underutilized crops have been proposed because of their likely suitability in these marginal areas of crop production characterized by abiotic (drought and heat) and biotic environmental stresses (pest and diseases). Bottle gourd is one such crop with multipurpose use and a huge potential to contribute to food security. The crop is grown for its leaves, fruits, and seeds from landraces providing important nutrition for both humans and livestock. A lot has been documented about its medical properties. The crop exhibits wide genetic variation for qualitative and quantitative traits, which can be used for cultivar development. The objective of this review was to provide information on why bottle gourd is an important food security crop in sub-Saharan Africa. The first section of the paper presents water scarcity, food production, and climate change. This is followed by the section on the neglected underutilized crops species. Then the section of drought tolerance of the crop is presented, and lastly, the section on potential contribution of the crop to food security is presented

Growth, morphological and yield responses of irrigated wheat (Triticum aestivum L.) genotypes to water stress

Water shortages is a major constraint in wheat production in South Africa. It is important therefore to assist irrigated wheat farmers to identify water stress tolerant growth stages in irrigated wheat genotypes. This study evaluated new wheat genotypes for water stress at different growth stages. An 8 (genotypes) × 2 (water treatments) × 3 (growth stages) factorial experiment was laid out in a randomised complete block design with three replicates. The results indicated that plant height was not affected (p > .05) by water stress at tillering and grain filling. Water stress imposed at the tillering stage reduced the number of fertile tillers (p .05). Aboveground biomass was only affected (p .05). This study provided evidence to suggest that most genotypes were tolerant to water stress at the flowering and grain filling stages

Postharvest effect of gaseous ozone on physicochemical quality, carotenoid content and shelf-life of mango fruit

AbstractThis study investigated the effect of gaseous ozone (O3) exposure time on the postharvest quality and shelf-life of mangoes. “Keitt” mango fruit harvested at physiological maturity was exposed to 0.25 mg/L of O3 for 12, 24,36, or 48 hours, and the control fruit were untreated. Fruit were thereafter stored at 10 ℃ for three weeks and ripened at ambient temperature for one week. Postharvest parameters such as mass loss, decay incidence, firmness, total soluble solids (TSS), titratable acidity (TA), and carotenoid content were assessed at weekly intervals. The findings showed that the physiological weight loss of untreated fruit (30.92%) was significantly higher (p <0.05) compared to O3 (12 h), O3 (24 h), O3 (36 h), and O3 (48 h) treated fruit, which was 28.49%, 25.90%, 20.54%, and 20.50%, respectively. Fruit treated with O3 (36 h) significantly maintained firmness, delayed TSS accumulation, and decreased loss of TA. The untreated fruit had a higher decay incidence compared to other treatments at the end of storage. Moreover, the total carotenoid content was notably higher in O3 (48 h) treated fruit during storage. Overall, the results demonstrated that the shelf-life of mango fruit was longer under the 36 h and 48 h treatments. These research findings indicate that O3 could be used effectively to maintain the postharvest quality and extend the shelf-life of mango fruit. Therefore, O3 (36 h) is recommended as a cost-effective postharvest treatment for “Keitt” mangoes

Long-term impact of no-till conservation agriculture on abundance and order diversity of soil macrofauna in continuous maize monocropping system

Unsuitable soil management in agriculture is known to results in the deterioration of soil health and the decline of biodiversity. The experiment tested whether no-tillage with mulch (NT), could boost biological activity of soil macrofauna population in continuous maize monocropping system compared with rotational tillage with mulch (RT) and conventional tillage (CT). Soil macrofauna was sampled at the end of the 2014/2015 growing season using 25 × 25 × 25 cm steel monoliths. The mean density of individual orders was higher (p < 0.001) under NT (46%) and RT (38%) compared with CT (16%). However, the Shannon-Weaver index revealed that the diversity and evenness of orders were similar for all treatments. Macrofauna patterns revealed that NT and RT contained higher (p < 0.001) population of Isoptera and Diplopoda. Isoptera was 51% and 17% higher in NT than CT and RT, while in Diplopoda, NT was 39% and 2% higher than CT and RT, respectively. It was concluded that NT and RT systems favoured the development of macrofauna communities in the studied maize continuous monoculture cropping system but did not favour order diversity of macrofauna. This suggests the importance of crop rotation for the development of the more diverse macrofaunal population

Physico-Chemical Analysis of Vermicompost Mixtures

The study evaluated the physical and chemical characteristics of vermicompost mixtures to optimize nutrient extraction. Three compost mixtures (chicken plus horse (CH+H), chicken plus cattle (CH+C), and cattle plus horse (C+H)) were selected for quality evaluation at three extraction times: 24, 48, and 72 h. The results showed differences (p p 3, P, K, Ca, Mg, Mn, and Cu) at 72 h, it was concluded that 48 h is the best time to extract nutrients from compost mixtures to produce good quality compost using aerobic extraction method