Color Index Research Articles

Pre-Treatment, Extraction Solvent, and Color Stability of Anthocyanins from Purple Sweetpotato.

Purple sweetpotato anthocyanins (PSPA) exhibit significant potential as food colorants with associated health benefits. However, challenges related to browning and instability have hindered the application of PSPA. In this study, various pre-treatments and solvents for PSPA extraction were evaluated based on color, anthocyanin yields, antioxidant capabilities, and brown index. Browning markedly influenced the color and reduced the antioxidant capacity. Optimal results were obtained with the pre-treatment of "steaming of unpeeled whole sweetpotato" and the solvent "1% citric acid-ddH2O". Furthermore, the color stability of purified PSPA solutions was evaluated under pH levels from 1 to 13 at 25 °C and 65 °C. The PSPA solutions showed a color spectrum from magenta, blue/green, and then to yellow across the pH range. The blue/green hues at pH 10-12 rapidly degraded, while the magenta hue at lower pH showed higher color stability. Elevated temperatures significantly accelerated the PSPA degradation. However, PSPA solutions at pH 1-2 exhibited remarkable color stability, with no spectral decay at either 65 °C for 12 h or 25 °C for 32 days. These results provide valid guidance for the extraction, preservation, and application of PSPA in the food industry.

Comparison of phenotypic variability of winter durum wheat varieties and lines according to the color characteristics of grain, cereals and pasta

There have been given the study results of grain color characteristics of winter durum wheat varieties and lines (Triticum durum Desf.). There has been studied the effect of factors (‘variety’, ‘year’ and their correlation) on the expression of the main breeding-valuable traits that affect the quality of the final product. The purpose of the current study was to determine the variability of phenotypic characteristics of grain associated with the number of yellow pigments in grain, the color of semolina and finished pasta, to study the correlation between indicators and to identify the most promising ones for further work. Field trials were carried out in the scientific crop rotation laboratory of breeding and seed production of winter durum wheat of the FSBSI “ARC “Donskoy”. Laboratory and analytical study was carried out in the laboratory of biochemical, technological and agrochemical estimation in accordance with generally accepted methods and GOST. As a result of the study, there has been established that the main effect on such characteristics of grain quality of winter durum wheat as ‘general hardiness’, ‘mass fraction of protein in grain’ and ‘grain color index b’ was produced by the factor ‘year of study’ by 67.0 %, 48 .2 % and 65.4 % respectively. The ‘cereal color index b’, ‘dry pasta color index b’ and visual estimation of dry pasta were mainly influenced by the factor ‘genotype’ by 62.3 %, 82.5 % and 48.3 %, respectively. The severity of the trait ‘content of carotenoid pigments’ depended on all factors. Over the years of the study, the winter durum wheat varieties and lines developed by the FSBSI “ARC “Donskoy” according to color characteristics met the international requirements for durum wheat grain. As a result, the varieties ‘Grafit’ and ‘Karotinka’ stood out according to several studied characteristics in connection with which we recommend expanding the production crops of these varieties. There can be recommended to use promising lines 1147/19 and 971/19 and the variety ‘Solntsedar’ in the breeding process as sources with high color characteristics of grain and pasta.

Educational Strategies to Increase the Acceptability of Products with Vegetables among Children

This study aimed to evaluate the effect of different educational techniques on the acceptability of products made with spinach among schoolchildren and analyze their physicochemical composition. Muffins and pancakes containing spinach were developed. Two hundred and fifty children were organized into five groups: Control Group (CG), sensory analysis of the products without any educational action; Group 1 (G1), theoretical activity; Group 2 (G2), cooking workshops; Group 3 (G3), implementation and cultivation of school vegetable garden; Group 4 (G4), cooking workshops and implementation of vegetable garden. Then, the children evaluated the food products sensorially. The combination of workshop and garden (G4) increased the acceptability of the muffin for aroma, color, and global acceptance and acceptability index (p < 0.05). The isolated interventions of workshop (G2), garden (G3), and both (G4) improved the acceptance of the taste, with no significant difference between the scores of the groups for appearance and texture in the muffin (p > 0.05). Superior scores for the appearance and aroma of the pancake (p < 0.05) were observed in G4 compared to CG. G4 also showed better acceptance for color, global acceptance, and acceptability index when compared to CG, G1, and G3. Aroma and texture were not influenced by the interventions (p > 0.05). In conclusion, the cooking workshop and the vegetable garden combined are superior in increasing the sensory acceptance of food products to which vegetables with low acceptability among children are added. The preparations have a favorable nutritional profile and can be offered to children.

GROWTH PERFORMANCE, CARCASS TRAITS, MEAT QUALITY AND HISTOCHEMICAL CHARACTERISTICS OF MUSCLE FIBERS IN MEXICAN HAIRLESS FINISHING PIGS SUPPLEMENTED WITH ORGANIC COPPER

<p><strong>Background:</strong> Pork meat is related to cardiovascular diseases, due to its high content of saturated fatty acids and cholesterol. But it has been shown that dietary supplementation of pigs with organic minerals benefits growth qualities and improves carcass and meat quality characteristics. <strong>Objective:</strong> The objective was to evaluate the effect of Cu proteinate supplementation of finishing Mexican Hairless pigs (MHP) on growth, carcass characteristics, meat quality and muscle fiber composition. <strong>Methodology:</strong> Twenty-eight castrated male MHP (62±5.2 kg BW) were randomly assigned to four levels of Cu in the diet (0, 75, 150, and 225 mg kg<sup>-1</sup> DM) for 46 d. The DMI, DWG, FC and FE were measured. At the end of fattening, the pigs were slaughtered and the characteristics of the carcass were evaluated. Tissue samples of <em>Longissiumus thoracis</em> (LT) were obtained and muscle fibers, pH, color, temperature and drip loss were evaluated. <strong>Results:</strong> The DMI was reduced linearly (<em>P</em>≤0.05) as Cu level supplementation increased in the diet. Growth performance was modified quadratically as Cu level supplementation was increased in the diet, as well as the highest DWG and the lowest FC values were found in barrows supplemented with 75 mg Cu kg<sup>-1</sup> DM. Pigs supplemented with 75 and 150 mg Cu kg<sup>-1</sup> DM had the highest (<em>P≤</em>0.05) CW and LEA compared with the other treatments. BFT and DL decreased linearly (<em>P</em>≤0.05) as Cu supplementation increased in the diet. The Cu supplementation affected (<em>P</em>≤0.05) the color index <em>b</em> and <em>h</em> after 48h. The Cu affected (<em>P≤</em>0.05) the number, composition and relative area of the type I, IIA and BII fibers of the LT. <strong>Implications: </strong>Organic Cu supplementation in the diet of Mexican Hairless pigs benefits growth efficiency, carcass yield and backfat reduction; however, its effect on content, FA profile, and oxidative stability of IF meat should be analyzed. <strong>Conclusions:</strong> It is concluded that Cu supplementation effected quadratically the values of Final BW, DWG, CW and LEA, and linearly Cu affected the values of DMI, FC, CCD, BFT, DL, pH, the color index <em>b</em> and <em>h</em> after 48h; treatments with Cu also influenced linearly or quadratically the number, composition and relative area of the type I, IIA and BII fibers of the LT post slaughter muscle metabolism and it may influence the parameters of quality of meat in finishing Mexican Hairless pigs. The production of MHP meat in an intensive fattening system is profitable and can be improved with the inclusion of Cu proteinate in the diet. </p>

Physicochemical Quality and Thermal Stability of Vegetable Oils during Deep-Fat Frying of Potato Chips

Background: Deep-fat frying induces organoleptic and physicochemical changes in both oils and fried products. Excessive use of frying oils accrues decomposition products with potential hazards to human health. Optimizing frying conditions and selecting the best frying oils are needed for better-fried products. Objective: This study was conducted to investigate the physicochemical changes and thermal behavior of vegetable oils (olive, canola, corn, sunflower and soybean oils) during deep-fat frying of potato chips, and determine the optimum conditions required to produce the best quality fried product. Methods: Thermal behavior, organoleptic characteristics, physicochemical properties (color index, viscosity, specific gravity, peroxide value, free fatty acids, total polar compounds), and fatty acid compositions of oils were investigated during the frying process every 8 hours up to 40 hours of heating. Results: Oils showed different quality and thermal stability. The optimum time and temperature for frying were 10 minutes and 180°C. Sensory attributes, physicochemical characteristics and fatty acid composition of oils were markedly affected by heating. Olive oil was the most stable for frying. Total polar compounds of 27% (the rejection point for frying oils) would be reached upon heating olive oil at 180°C for 114 hours. The corresponding times were 45, 43, 30 and 26 hours for canola, corn, sunflower and soybean oils, respectively. Conclusion: Olive oil showed the highest stability and produced the best-fried product, followed by canola oil. Frying time increased with extended heating, and it could be used as a good indicator of oil quality and when it should be discarded.

Egg Quality Parameters Evaluation of Indigenous and Sasso Chicken in Sidama Region, Ethiopia

A study was conducted at Aleta Wondo district of Sidama Region to evaluate quality parameters of eggs collected from indigenous and Sasso chickens reared under a traditional management system. About 100 eggs from each chicken type were collected from households who keep indigenous or Sasso chicken. Eggs were transported to Hawassa university poultry farm for quality parameters analysis. External and internal egg quality analysis was done according to laboratory procedure. Collected data was analyzed using SAS (Version 9.0). Results indicated that eggs collected from Sasso chicken showed superiority over indigenous chicken’s eggs for egg weight, egg length, egg width, shell weight, shell thickness and surface area. There is no significant difference on shape index and shell percentage of eggs collected from indigenous and Sasso chickens. Shape index recorded was 72.66 and 74.04 for indigenous and Sasso chickens respectively. Albumen weight was statistically higher for eggs collected from Sasso chickens (P<0.0001). Eggs from indigenous chickens have superiority over Sasso’s eggs for yolk ratio, Haugh Unit and yolk albumen ratio. However, there is no significant variation on albumen height, yolk weight, yolk height, yolk color, yolk diameter and yolk index. It can be concluded that Sasso chicken produce heavier eggs than indigenous chicken. Yolk related parameters are similar for indigenous and Sasso chicken eggs produced at traditional management system.

The effect of breeds and rearing system on laying performance and egg quality of local chickens

The study was to identify the reproductive performance of Vietnamese local chickens, named Noi chickens from 36 - 46 weeks of age. The study aimed to determine the effect of breeds and rearing system on laying performance and egg quality of local chickens. The study was a factorial design with 2x2 factors and involved with 120 layers. The first factor was 2 rearing systems (experimental free-range farming system in Tra Vinh province and local free-range farming system in Ben Tre province). The second factor was 2 breeds (egg and broiler purpose). The results showed that egg production rate, laying egg per week were significantly different between breeds and rearing systems (P<0.05) while feed intake was not different. The highest egg production rate recorded at week 44 with 38.42%. For egg quality, yolk diameter, yolk color and yolk index were different breeds and rearing system. It can be recommended that rearing system in Ben Tre province and egg purpose breed was better for egg production and quality.

Vegetation and Dormancy States Identification in Coniferous Plants Based on Hyperspectral Imaging Data

Conifers are a common type of plant used in ornamental horticulture. The prompt diagnosis of the phenological state of coniferous plants using remote sensing is crucial for forecasting the consequences of extreme weather events. This is the first study to identify the “Vegetation” and “Dormancy” states in coniferous plants by analyzing their annual time series of spectral characteristics. The study analyzed Platycladus orientalis, Thuja occidentalis and T. plicata using time series values of 81 vegetation indices and 125 spectral bands. Linear discriminant analysis (LDA) was used to identify “Vegetation” and “Dormancy” states. The model contained three to four independent variables and achieved a high level of correctness (92.3 to 96.1%) and test accuracy (92.1 to 96.0%). The LDA model assigns the highest weight to vegetation indices that are sensitive to photosynthetic pigments, such as the photochemical reflectance index (PRI), normalized PRI (PRI_norm), the ratio of PRI to coloration index 2 (PRI/CI2), and derivative index 2 (D2). The random forest method also diagnoses the “Vegetation” and “Dormancy” states with high accuracy (97.3%). The vegetation indices chlorophyll/carotenoid index (CCI), PRI, PRI_norm and PRI/CI2 contribute the most to the mean decrease accuracy and mean decrease Gini. Diagnosing the phenological state of conifers throughout the annual cycle will allow for the effective planning of management measures in conifer plantations.

Water quality monitoring of large reservoirs in China based on water color change from 1999 to 2021

Water color is an essential indicator of water quality, and research methods of water color based on remote sensing have become a trend in large-scale water quality monitoring. Large reservoirs are important for regional development. However, large-scale research into the quality of the water is lacking. Accordingly, to study the spatiotemporal water quality conditions of large reservoirs in China, this study conducted an inversion of water color over the past 23 years. Using Landsat series images, the Dynamic Surface Water Extent (DSWE) algorithm, and the Forel-Ule index (FUI), the water surface of 746 large reservoirs in China was sampled and the water color was inverted using the Google Earth Engine (GEE) platform. The FUI local change index was established to analyze changes over time. The results showed that the annual average FUI value of large reservoirs in China was less than 11, showing non-eutrophic and green water bodies. From the water color analysis of 91 large Type I reservoirs, it was found that the water quality of the reservoirs in the Northeast region was poor (FUI greater than 12), with many aquatic plants and algae or highly turbid and greenish-brown waters, mainly for flood control and irrigation. In southern China, there were primarily mesotrophic and oligotrophic reservoirs (FUI not greater than 8) with green or greenish-blue water color, which were mainly used for water supply and power generation. The construction of the southern reservoirs reduced the FUI values by an average of five levels, apparently changing the water color. The FUI local change index revealed that the FUI values of large reservoirs in China showed an overall decreasing trend from 1999 to 2007, stabilized after 2007, and then fluctuated after 2013. This study also found that the water color index of large reservoirs in China is positively correlated with the trophic status and turbidity of water bodies to some extent. Therefore, this study can compensate for the lack of water color remote sensing in large-scale reservoir water quality studies and support large-scale reservoir monitoring and management.

Fabrication of freshness indicators based on methylcellulose-containing color indicator solutions for monitoring the quality of coconut water

This is the first study to apply intelligent packaging to coconut water. The purpose of this study was to determine the best color indicator solution for making freshness indicator labels based on methylcellulose along with the color change profile of coconut water during storage at room temperature. Three color indicator solutions were used, namely phenol red, bromothymol blue, and methyl red, which were then continued with the fabrication of freshness indicator labels based on methylcellulose from each of these color indicator solutions and applied to coconut water at 25 °C room temperature storage for 24 h with observations every 4 h in the form of pH, total dissolved solids, total acid, turbidity, total microbes, CO2 gas, O2 gas, and freshness indicator label color changes. The values of pH, total soluble solids, and O2 gas decreased with storage time, whereas the values of total acid, turbidity, total microbes, and CO2 gas continued to increase. The methylcellulose-based phenol red freshness indicator label provides the best color change profile that matches the freshness condition of coconut water, namely purplish red (fresh), orange (immediately consumed), and yellow (damaged) so that it can be used as intelligent packaging to monitor the quality of coconut water.

Progressive stirred freeze concentration: Effect of operative parameters on vital statistics of beer

AbstractFreeze concentration (FC), a low‐cost alternative technology to separate and concentrate high‐value compounds, was applied to three distinct craft ale beer styles—Witbier, Bitter, and Porter—to investigate its impact on vital beer statistics. A central composite design with freezing temperature and ice fraction as factors was employed, with response surface analysis revealing significant effects on the average ice growth rate (), concentration index (CI), and average distribution coefficient () of ethanol, total solids, color, and bitterness in the liquid fraction. Results showed that ice fraction primarily influenced solute concentrations and increased with ice fraction due to water removal. Freezing temperature affected . The type of beer had a significant impact on color and bitterness, reflecting the specific style parameters. Furthermore, response optimization yielded conditions that significantly altered beer statistics, leading to changes in ethanol content, total solids, color, and bitterness, possibly classifying them as new beer styles. The study demonstrates the potential of FC to influence the beer characteristics and broaden the range of beer styles.Practical applicationsInnovations in science and technology, added to the search for new beer styles, promote the development of new products in the beer industry. In this article, a potential use of the freeze concentration technology was identified for the development of new concentrated beer products. The impact of progressive stirred freeze concentration in three craft beers was studied. First, obtaining a concentrated beer from this technique was possible, with a higher concentration of total solids and ethanol. In addition, the vital statistics of beer could be modified using freeze concentration to obtain novel concentrated beer products.

Distant activity of long-period comets C/2019 L3 (ATLAS) and C/2020 P3 (ATLAS)

ABSTRACT Long-period comets C/2019 L3 (ATLAS) and C/2020 P3 (ATLAS) remain active at heliocentric distance greater than 4 au. Broad-band Charge-Coupled Device (CCD) photometry of long-period comets C/2019 L3 and C/2020 P3 is analysed in this paper. The observation was obtained with three telescopes: ZEISS-1000 at Simeiz Observatory, Maksutov at Abastumani Astrophysical Observatory, and ZTSh at Crimean Astrophysical Observatory. The R-band A(0)fρ values of C/2019 L3 range from (5043 ± 244) to (13611 ± 1874) cm, and tend to decrease first and then increase. The average colour indices of C/2019 L3 are B–V = 0.75 ± 0.06, V–R = 0.28 ± 0.05, and R–I = 0.21 ± 0.05. The reddening of C/2019 L3 exhibits variations during the observational runs, ranging from (13.75 ± 1.07) to (−15.69 ± 0.37) per cent/kÅ with an average value of (0.94 ± 0.23) per cent/kÅ. It possesses a non-steady coma since the average gradient of its surface brightness profile is −1.60. For comet C/2020 P3, its R-band A(0)fρ values range from (606 ± 31) to (869 ± 20) cm, the colour indices are B–V = 1.04 ± 0.09, V–R = 0.26 ± 0.05, and R–I = 0.76 ± 0.04, and the reddening is (−6.65 ± 0.01) per cent/kÅ. The colour indices of the two comets differ from those of other long-period comets. Compared with other long-period comets, comet C/2019 L3 is very active at heliocentric distance of ∼4 au, while C/2020 P3 is moderately active at heliocentric distance of ∼7 au.

Light influences the effect of exogenous ethylene on the phenolic composition of Cabernet Sauvignon grapes.

The gaseous phytohormone ethylene (ETH) plays a key role in plant growth and development, and is a major regulator of phenolic biosynthesis. Light has long been known to influence phytohormone signaling transduction. However, whether light influences the effect of ETH on the phenolic composition of grapes (Vitis vinifera L.) is an open question. Here, the accumulation and composition of anthocyanins and non-anthocyanin phenolics were analyzed in Cabernet Sauvignon grapes under four treatments: light exposure with and without ETH treatment, and box-shading with and without ETH treatment. Both light and ETH promoted ripening, decreased the color index (L*, C*, and h*), and accelerated the color change from green to red and purplish red. Sunlight-exposed grapes had the highest contents of most anthocyanins, flavonols, flavan-3-ols, and hydroxybenzoic acids. In addition, light exposure increased the ratios of 3'5'-substituted/3'-substituted anthocyanins and flavonols, but decreased the ratios of methoxylated/non-methoxylated and acylated/non-acylated anthocyanins and flavan-3-ols. Notably, the effects of ETH were influenced by light exposure. Specifically, ETH treatment promoted anthocyanin and non-anthocyanin biosynthesis in light-exposed grapes, and their increasing multiples were remarkably higher under light-exposed conditions. Furthermore, ETH treatment decreased the ratios of methoxylated/non-methoxylated, 3'5'-substituted/3'-substituted, and acylated/non-acylated anthocyanins and flavan-3-ols in light-exposed grapes, each of which was increased by ETH treatment in shaded grapes. Fifteen differential phenolic components were identified through partial least-squares-discriminant analysis (PLS-DA). Among them, cyanidin-3-O-(cis-6-O-coumaryl)-glucoside, petunidin-3-O-(6-O-acetyl)-glucoside, petunidin-3-O-(trans-6-O-coumaryl)-glucoside, petunidin-3-O-glucoside, myricetin-3-O-galactoside, kaempferol-3-O-galactoside, and kaempferol-3-O-glucoside were the main differential components between ETH treatments under different light conditions. This study contributes to the understanding of the impact of ethylene treatment under dark and light conditions on phenolic synthesis in grape berries.

High-resolution climate change during the Marine Isotope Stage 3 revealed by Zhouqu loess in the eastern margin of the Tibetan Plateau

A consensus has not yet been reached on effects of climate change and driving mechanisms between the Tibetan Plateau (TP) and adjacent monsoonal areas during the Marine Isotope Stage 3 (MIS 3). Loess–paleosol sequences from the TP provide valuable information about the MIS 3 environmental history. Detailed color index and a diffuse reflectance spectral (DRS) analysis of Zhouqu (ZQ) loess from the Western Qinling Mountains were conducted to investigate climate change on the eastern margin of the TP during the MIS 3. Our results show that the variations in color index and iron oxide content in ZQ loess are mainly caused by the pedogenesis and climate conditions. The lightness (L*) value and hematite (Hm) content were used to reconstruct the precipitation history and temperature changes, respectively. The reconstructed records revealed that climate change during the MIS 3 was characterized by high frequency and large amplitude, with millennial-scale changes superimposed on orbital-scale changes. Warm–humid climate occurred in the late MIS 3, while the early climate of MIS 3 was relatively cold–dry. The Indian summer monsoon (ISM) and temperature variations during the MIS 3 mainly occurred due to obliquity and precession. The North Atlantic cooling led to the southward movement of the Intertropical Convergence Zone, and the downstream cooling of the atmosphere by the westerly jet could result in events on a millennial-scale in the eastern margin of the TP. The interhemispheric forcing may play an important role in driving the strong summer monsoon in the late MIS 3.

Metallicity Distribution in the LMC and the SMC Based on the Tip-RGB Colors

The color index (J − K)0 of tip-red-giant branch (TRGB) is used to study the metallicity distribution in the Large and Small Magellanic Cloud. With the most complete and pure sample of red member stars so far, the areas are divided into 154 and 70 bins for the LMC and SMC, respectively, with similar number of stars by the Voronoi binning. For each bin, the position of TRGB on the near-infrared color–magnitude diagram, specifically (J − K)0/K 0, is determined by the poison-noise weighted method. Converting the color index of TRGB into metallicity, the metallicity gradients in the LMC and the SMC are obtained in four major directions. For the LMC, the gradient to the north is −0.006 ± 0.004 dex kpc−1, to the south −0.010 ± 0.005 dex kpc−1, to the east −0.006 ± 0.003 dex kpc−1, and to the west −0.010 ± 0.003 dex kpc−1. The farthest distance extends to 16 kpc. For the SMC, the gradients to the north, south, east, and west are −0.017 ± 0.031 dex kpc−1, −0.016 ± 0.007 dex kpc−1, −0.003 ± 0.002 dex kpc−1, and −0.004 ± 0.003 dex kpc−1, respectively. The farthest distance for the SMC extends to 27 kpc. The gradient is large from the center to 1 kpc.

Bamboo as a substitute for plastic: Research on the application performance and influencing mechanism of bamboo buttons

In the context of the “bamboo as a substitute for plastic” initiative and global restrictions on plastic, the substitution of plastic buttons with bamboo buttons offers significant advantages in terms of resource efficiency, environmental impact, and ecological benefits. This study demonstrated the preparation of bamboo buttons by the manufacturing method of plastic buttons. Then the bamboo buttons were heat-treated to improve their application properties as garment fasteners. It was to explore the application performance and the underlying influencing mechanism of bamboo buttons, encompassing the morphology, physical and chemical properties, color variation, versatility in different scenarios, and mechanical properties of bamboo buttons. The findings demonstrated that heat treatment process had the potential to enhance the surface color uniformity and richness of bamboo buttons. Moreover, a satisfactory linear relationship was observed between the major components of bamboo buttons and the color index. Lignin played a major role in color index, which was negatively correlated with brightness index (L*) and yellow-blue index (b*), and positively correlated with red-green index (a*) and total chromatic difference (ΔEab*). Color variations were observed in bamboo buttons by washing with seawater, chlorine water, and soap (40 °C, 50 °C, 60 °C, and 95 °C). The tensile strength of the bamboo buttonhole gradually decreased from 291.84 ± 28.10 N to 136.69 ± 25.19 N as the temperature increased. However, bamboo buttons met the requirements for light duty applications. The fracture morphology of bamboo buttons was categorized into four forms: linearity, stair pattern, parallel lines, and Y shape. All broken bamboo buttons exhibited fractures along the fiber direction and within the intercellular layer, mainly attributed to the differences in chemical composition between the cell wall and the intercellular layer. This research could provide a theoretical foundation for the promotion and application of bamboo buttons.

Effect of temperature, 1-methylcyclopropene, and modified atmosphere packaging on the post-harvest behavior of lulo (Solanum quitoense Lam)

Lulo (Solanum quitoense Lam) is a tropical fruit with high market potential but short shelf life. In this work, the effect of temperature, the application of 1-methylcyclopropene (1-MCP), and the use of modified atmosphere packaging (MAP) were evaluated on the preservation of fresh lulo fruits. Three independent experiments were made sequentially: in the first one, an adequate refrigeration temperature was established (between 5 and 18 °C), then in the second experiment, a suitable dose and application time of 1-MCP (0.35–1.0 μL L−1 and 10–15 min) were found and finally, the combined effect of refrigeration, 1-MCP, and MAP were determined in the last experiment. In the experiments with 1-MCP and MAP, some fruits were stored at refrigeration (5 °C) and then at room temperature (23 °C) while others were kept at room temperature the whole test. Different properties such as respiration, ethylene production, color index, and gas level were evaluated in the samples to determine post-harvest changes. Given the fruit behavior during cold storage, 5 °C proved to be more favorable for preservation. Likewise, samples treated with 0.70 μL L−1 1-MCP + 15 min immersion showed lower CO2 and ethylene production throughout cold storage and shelf time compared with other 1-MCP treatments. For the tests with MAP, the combined treatment with 1-MCP and at 5 °C resulted in a lower respiratory rate, ethylene production, and physicochemical changes during the evaluation (24 days of cold storage + 16 days of shelf time). The results obtained can contribute to increasing the possibilities of lulo commercialization and marketing.

Allosteric strand displacement isothermal amplification for the visual detection of Toxoplasma gondii in 30 minutes

Early detection of Toxoplasma gondii (T. gondii) is critical due to a lack of effective treatment for toxoplasmosis.This study established a simple, cost-effective, and rapid colorimetric detection method for T. gondii. The entire testing process, from sample collection to results, takes only 0.5 h. These characteristics fulfill the demands of researchers seeking rapid target detection with minimal equipment reliance. For genomic extraction, this study evaluated the ability of two filter papers to capture genomes. A rapid genomic extraction device combined with the two filter papers was designed to simplify the genomic extraction process, which was completed within 10 min and increased the detection sensitivity tenfold. The method utilized a simplified primer design for isothermal amplification, namely allosteric strand displacement (ASD), and employed an underutilized commercial color indicator, Bromothymol Blue (BTB), for signal output. Compared with other reported indicators, BTB exhibited a more pronounced color change, shifting from blue to yellow in positive samples, facilitating easier visual differentiation. The reaction was completed in 20 min with a limit of detection (LOD) as low as 0.014 T. gondii per microliter.

Impact of deep-fat frying cycles on the physicochemical characteristics of two edible vegetable oils marketed in Algeria

Background: Vegetable oils containing polyunsaturated fatty acids are prone to oxidation when exposed to high-temperature frying processes. Aims: This study aims to follow the changes that occur in frying oil when used to fry potatoes. Material and Methods: The impact of the ratio of potatoes (g) to oil (g) as well as the number of frying cycles on the quality of two commonly marketed oils in Algeria: 100% soybean oil (oil A) and a blend of 60% soybean, 20% sunflower, and 20% corn oil (oil B) was assessed. The quality of these oils throughout repeated frying cycles was monitored by analyzing pH, density, color, moisture, acidity, peroxide value, saponification value, and acid index. Results: The results of the present study revealed that both oils experienced deterioration as the frying cycles were repeated, with more significant degradation observed with the 1/5 ratio of fries to oil compared to the 1/8 ratio. Remarkably, the 100% soybean oil deteriorated more rapidly than the oil blend. Conclusion: Based on the observed changes in physicochemical parameters and chemical indices, the use of frying oils beyond the third cycle significantly compromises their quality and safety. This not only impacts the consumer’s health but also the organoleptic properties of fried foods. Therefore, it is highly recommended to refrain from exceeding this limit to ensure optimal frying practices and protect consumer health. Keywords: Vegetable oils, deep-fat frying, ratio of fries/volume of oil, physical quality, chemical indices.

Effect of different sterilization methods on the appearance, composition, and flavor of sugarcane juice.

Cold-pressed sugarcane juice (SCJ) is a beverage rich in vitamins, carbohydrates, and antioxidants. Various sterilization methods impact fruit juice's appearance, nutrients, and flavor. Hence, this study aims to assess how different sterilization techniques affect the flavor, appearance, and nutritional value of SCJ. Freshly prepared SCJs were subjected to two sterilization methods: pasteurization (referred to as PTG) and autoclaving (referred to as HTHP). The pasteurization process was carried out at 63°C for 30min, whereas the HTHP process was applied at 115°C for 30min. The appearances, Brix value, colors, sugar, organic acid content, and aromatic compounds were determined. The Brix and pH values of the juice show little variation across different heat treatments. The color index of PTG was similar to that of the control group, whereas the L* value of HTHP increased about 21%, resulting in a significant color change. The glucose and fructose contents of HTHP were 7.03 and 5.41mg/mL, which were much higher than those of PTG (3.26 and 2.33mg/mL) and control group (3.33 and 2.48mg/mL). A total of 77 aromatic compounds were identified in the SCJ after various heat treatments. Among them, pentanoic acid, octanal, and β-damascenone were the most abundant substances contributing to the overall flavor in the control group, PTG, and HTHP. Pasteurization preserved the original flavor of the juice, whereas autoclaving triggered the Maillard reaction, forming pyrazine and furan-like compounds that altered the SCJ's flavor. In conclusion, pasteurization retained SCJ's original characteristics, whereas HTHP induces changes in nutrition and imparts a distinct flavor.