The Role of Cations in Resorcinol–Formaldehyde Gel Textural Characteristics

The production of resorcinol–formaldehyde xerogels has yielded insight into the gelation processes underpinning their structures. In this work, the role of the cation species from the catalyst is probed by studying the simultaneous addition of sodium carbonate and calcium carbonate to a resorcinol–formaldehyde mixture. Twenty-eight xerogels were prepared by varying the solids content, catalyst concentration, and catalyst composition, and each was analysed for its textural properties, including the surface area and average pore diameter. The results indicate that the role of the cation is linked to the stabilisation of the clusters formed within the system, and that the Group II catalyst causes the salting out of the oligomers, resulting in fewer, larger clusters, hence, an increase in pore size and a broadening of the pore size distribution. The results provide insight into how these systems can be further controlled to create tailored porous materials for a range of applications.

Interactions of Linearly Polarized and Unpolarized Light on Kiwifruit Using Aquaphotomics

Near infrared (NIR) spectroscopy is an important tool for predicting the internal qualities of fruits. Using aquaphotomics, spectral changes between linearly polarized and unpolarized light were assessed on 200 commercially grown yellow-fleshed kiwifruit (Actinidia chinensis var. chinensis ‘Zesy002’). Measurements were performed on different configurations of unpeeled (intact) and peeled (cut) kiwifruit using a commercial handheld NIR instrument. Absorbance after applying standard normal variate (SNV) and second derivative Savitzky–Golay filters produced different spectral features for all configurations. An aquagram depicting all configurations suggests that linearly polarized light activated more free water states and unpolarized light activated more bound water states. At depth (≥1 mm), after several scattering events, all radiation is expected to be fully depolarized and interactions for incident polarized or unpolarized light will be similar, so any observed differences are attributable to the surface layers of the fruit. Aquagrams generated in terms of the fruit soluble solids content (SSC) were similar for all configurations, suggesting the SSC in fruit is not a contributing factor here.

Evaluating the Physicochemical Properties of Some Kosovo’s and Imported Honey Samples

This study evaluated the physicochemical properties (moisture, pH, electrical conductivity, free acidity, hydroxymethylfurfural (HMF), proteins, insoluble solids, and ash) of 45 Kosovo’s and imported honey samples, using methods provided by national and international standards. The moisture values of all honey samples analyzed were below 20%. The free acidity was above 50.0 meq kg−1 in 14 out of 33 samples (42%) collected in Kosovo, while 2 out of 12 imported honey samples (16.7%) showed higher values than 50 meq kg−1. In this study, 7 out of 33 honey samples (21%) from Kosovo and one out of 12 honey samples from imports had soluble solids content below 80 °Brix. In terms of HMF, 5 out of 33 Kosovo honey samples (15%) and 4 out of 12 imported honey samples (33%) exceeded 40 mg/kg, which is the maximum content of HMF set in standards. The values of some physicochemical parameters (free acidity, HMF, and soluble solids) of local and imported honey samples are not within the quality limits set in legislation. Further studies are needed to evaluate the properties of fresh honey produced in Kosovo and the stability of honey during prolonged storage.

Does the Addition of Cellulosic Micro/nanofibrils Improve the Properties of Hydroxypropyl Methylcellulose Films?

Damages to ecosystems, due to the consumption of petroleum-based materials, can be mitigated with the use of biopolymers such as cellulose derivatives. The objective was to evaluate the influence of different proportions of cellulose micro/nanofibrils (MFC/NFC) on the properties of hydroxypropyl methyl cellulose (HPMC) films. Films were prepared using proportions of 0, 25, 50, 75 and 100% (w/w) of MFC/NFC of Pinus sp. in relation to HPMC. The physical, barrier, surface, optical, morphological and mechanical properties were evaluated. Data were analyzed with descriptive statistics, linear regression, principal component analysis and Pearson correlation. Solids content, basis weight and density values increased with higher MFC/NFC amount, while thickness and porosity were reduced. SEM images showed that films with more than 50% MFC/NFC had a more granular surface resulting in reduction of transparency from 80 to 65%. The water vapor penetration did not differ between films and the degradation in water was reduced from 40 to 5% as MFC/NFC was added. There were no differences for contact angle and wettability, but all films showed high resistance to fat penetration. Films with MFC/NFC contents between 75 and 100% showed higher values for tensile strength (50 to 65 MPa) and Young's modulus (6 to 10 MPa) and lower elongation at break (1 to 2%). The experimental results indicated that films with MFC/NFC contents above 50% have potential to be used as packaging material.

Application methods of biostimulants affect the production and postharvest conservation of yellow melon

Worldwide, Brazil holds the fifth position in melon fruits exportation, further expanding its products to provide for the growing demand. This expansion is the result of the development and application of new technologies, including the management of the use of biostimulants. However, for melon crops, the information in the literature on the use of biostimulants remains limited to the effects of different doses on fruit quality at the time of harvest. Therefore, this study aimed to evaluate the influence of different methods of pre-harvest application of two biostimulants on the production and postharvest conservation of fruits of yellow melon cv. Iracema. The treatments consisted of a combination of three factors: two plant biostimulants (Crop Set® and Spray Dunger®), two application methods of the products (fertigation and spraying), and five times of postharvest storage (0, 14, 21, 28 and 35 days). An additional control treatment corresponded to plants without biostimulant application. The fruits were evaluated for production and physicochemical attributes: average mass, yield, flesh firmness, titratable acidity, soluble solids content, SSC/TA ratio, pH, total soluble sugars, and weight loss. Fertigation is the recommended application method of biostimulants for yellow melon due to its effect on the increase of average mass, yield, flesh firmness, soluble solids content, and total soluble sugars of the fruits in relation to the spraying method.

Fundamental Studies on CO2 Sequestration of Concrete Slurry Water Using Supercritical CO2

To prevent drastic climate change due to global warming, it is necessary to transition to a carbon-neutral society by reducing greenhouse gas emissions in all industrial sectors. This study aims to prepare measures to reduce the greenhouse gas in the cement industry, which is a large source of greenhouse gas emissions. The research uses supercritical CO2 carbonation to develop a carbon utilization fixation technology that uses concrete slurry water generated via concrete production as a new CO2 fixation source. Experiments were conducted using this concrete slurry water and supernatant water under different conditions of temperature (40 and 80 °C), pressure (100 and 150 bar), and reaction time (10 and 30 min). The results showed that reaction for 10 min was sufficient for complete carbonation at a sludge solids content of 5%. However, reaction products of supernatant water could not be identified due to the presence of Ca(HCO3)2 as an aqueous solution, warranting further research.

A detergent for mango fruit sap-induced injury

This study determined the optimum concentration of, and duration of immersion in a local detergent (“awabla”) that protected fruit skin of Kent and Keitt mango varieties from mango fruit sap-induced injury (sap-burn) at harvest.The resultant skin/peel colour, pulp colour, and total soluble solids content was also evaluated for fruit quality. Randomized Complete Block Design and Completely Randomized Design with four replications in each case were used for field and laboratory experiments respectively. For each of the two varieties, ten mango trees were sampled at random in each of the four replications of a mango plantation.On each sample tree, twenty panicles all initiating fruit-set were identified and tagged. The number of days from fruit-set to physiological maturity were monitored and harvested for the experiments. Concentrations of 0.25,0.50, and 0.75% of “awabla” solution for 25,30,and35 minutes immersion period in all combinations were established as appropriate and recommended for management of Kent and Keitt mango fruit sap-induced injury. The detergent (“awabla”) had a proven efficacy in the range of 87-94 % for Kent and 90-93 % for Keitt. The resultant peel colour, pulp colour, and total soluble solids content of Kent and Keitt mango fruit samples were not significantly influenced by the treatments at p>0.05.