Color Parameters Research Articles

Physicochemical, Antioxidant, Organoleptic, and Anti-Diabetic Properties of Innovative Beef Burgers Enriched with Juices of Açaí (Euterpe oleracea Mart.) and Sea Buckthorn (Hippophae rhamnoides L.) Berries

Background: The aim of this study was to evaluate the selected quality parameters of innovative beef burgers produced with the addition of açaí and/or sea buckthorn berry juices. Methods: Five variants of innovative burgers were obtained, differing in the proportion of juices in the recipe. The pH of meat stuffing, thermal losses, production yield, color (CIE L*a*b*), content of polyphenolic compounds, degree of oxidation of the lipid fraction (TBARS), and antioxidant activity against ABTS radicals were determined. Anti-diabetic activity was measured as the ability to inhibit α-glucosidase and dipeptidyl peptidase−4 activity. A sensory evaluation was also performed. Results: Beef burgers formulated with açaí and sea buckthorn juices had up to five times higher total polyphenol content than burgers without added juices. The addition of the juices increased antioxidant activity against ABTS radicals (from 42 to 440 µmol/L/100 g) and effectively inhibited oxidation of the lipid fraction of the beef burgers. Recipe modifications resulted in changes in the color parameters of the beef burgers and had a positive effect on the sensory quality attributes evaluated. Beef burgers containing 0.5 g of açaí juice and 1.0 g of sea buckthorn juice were rated the best in terms of acceptability of appearance, aroma, color, juiciness, and tenderness. The addition of açaí and sea buckthorn juice did not increase the inhibitory activity against α-glucosidase and dipeptidyl peptidase-IV of the innovative beef burgers. Conclusions: The proposed recipe modification may be an effective way to fortify beef burgers with phytochemicals with antioxidant properties while maintaining their sensory properties.

Extraction of dye sorghum biocolorant for the dyeing of wagashi, a West African soft cheese

We developed a sustainable method to extract the red biocolorant from dye sorghum leaf sheaths for dyeing wagashi, a West African soft cheese. The pigments were extracted using three different solvents: commercial ethanol (method A), sodabi (a local liquor distilled from palm wine; method B) and aqueous alkaline solvent (method C). In methods A and B, a pot still was used to distil and collect the solvent for reuse. The obtained extracts were used to dye wagashi at various concentrations. The yield and colour characteristics of the extracts were evaluated and the physicochemical characteristics of the dyed wagashi were recorded and compared to commercial wagashi sold in the local market. The solvent recovery in methods A and B was 96 % and 47 %, respectively. Extraction of anthocyanin pigments was highest with method A, namely 21 mg mL−1 for total phenolics against 13.4 and 1.64 mg mL−1 for methods B and C, respectively. The colour parameters suggested a similar colour for all the extracts, but the redness index of the extract from method B was significantly higher than that of the other methods. Wagashi dyed with extracts from methods B and C had similar colour characteristics and were comparable to the best-coloured commercial wagashi from the Parakou market based on the chroma and the hue angle values of the chromaticity diagram. Despite the lower colouring power of extracts made by method B, we consider this method the best when taking into account the cost and availability of the solvent. In conclusion, the application of sodabi extract at a dose of 200 mL L−1 is recommended to dye wagashi.

Colour Analysis of Sausages Stuffed with Modified Casings Added with Citrus Peel Extracts Using Hyperspectral Imaging Combined with Multivariate Analysis

Recycling citrus peel waste offers several significant contributions to sustainability, transforming what would otherwise be discarded into valuable resources. In this study, the colour of sausages stored for 16 days, with varying amounts of orange extract added to the modified casing solution, was evaluated using response surface methodology (RSM) and a hyperspectral imaging system within the spectral range of 350–1100 nm for the first time. To enhance model performance, spectral pre-treatments such as normalisation, first derivative, standard normal variate (SNV), second derivative, and multiplicative scatter correction (MSC) were applied. Both raw and pre-treated spectral data, along with colour attributes, were fitted to a partial least squares regression model. The RSM results indicated that the highest R2 value, 80.61%, was achieved for the b* (yellowness) parameter using a second-order polynomial model. The interactive effects of soy oil and orange extracts on b* were found to be significant (p < 0.05), and the square effects of soy oil on b* were significant at the 1% level. The identified key wavelengths for colour parameters can simplify the model, making it more suitable for practical industrial applications.

The Assessment of the Possibility of Using Yellow Mealworm Powder in Chicken and Pork Pâté Production

Meat delicatessen products, including pâtés, are important for consumers’ daily diets. However, due to the complex recipe composition, pâtés can also contain allergens such as gluten. Simultaneously, powdered edible insects are increasingly used to reformulate food products. Therefore, the paper aimed to investigate the feasibility of replacing wheat flour (total content: 9% w/w) with yellow mealworm powder (3:0, 2:1, 1:2, and 0:3) in chicken and pork pâtés and determine its effect on their quality properties. The rheological properties of pâté batter, as well as texture, color parameters, and microbiological and sensory characteristics of pâtés, were assessed. All prepared pâté batters were identified as weak gels. Furthermore, all the examined pâtés met the microbiological quality requirements. Adding yellow mealworm powder to the formulation weakened the pâté structure, resulting in significantly lower shear force and increased spreadability. In addition, it led to a darker and more gray color of the pâtés. It may be seen as indicating no preservatives or as resembling a typical pork pâté. It has been demonstrated that the complete replacement of wheat flour with insect powder significantly reduced the sensory quality of chicken and pork pâtés.

Fungal Biostarter and Bacterial Occurrence of Dry-Aged Beef: The Sensory Quality and Volatile Aroma Compounds after 21 Days of Aging

In this study, we decided to test the hypothesis that the fungal biostarter M. flavus used during a 21-day beef dry-aging process significantly impacts the composition of other microorganisms, the profile of volatile compounds, meat hardness characteristics, and, consequently, the sensory quality. The experiments were performed on samples derived from animals crossbred between Holstein–Fresian cows and meat breed bulls. Two groups of samples were studied, including the control group, without biostarter, and a group inoculated with the M. flavus biostarter. Both sample groups were seasoned for 21 days in the dry-aging fridge. The physicochemical parameters (pH, color parameters), the chemical composition of muscle, the determination of the shear force, the profile of volatile compounds (VOCs), and the sensory quality were evaluated after aging. During this study, classical microbiological methods were used to investigate the influence of fungal biostarters on the growth and survival of bacteria and other fungi (e.g., yeasts) during the dry-aging process of beef (DAB). The M. flavus biostarter improved the sensory quality of DAB, allowing high sensory quality to be achieved after just 21 days. This is likely due to the diverse VOCs produced by the fungus, including 1-tetradecanol, 2-nonenal, trans-2-undecenoic acid, and the following esters: formic acid hexyl ester, 10-undecenoic acid methyl ester, and 4-methylpentanoic acid methyl ester. The presence of the biostarter had no significant effect on the number of the bacteria or the survivability of the L. monocytogenes on the meat’s surface in laboratory conditions.

The efficacy of power ultrasound treatment in preserving quality of fresh-cut cucumbers

The impact of power ultrasound (PU), antibrowning agents, and hot-water bath at 65?°C on the inhibition of enzymatic browning and 10 days product-life analysis of freshly cut cucumber samples were determined. The observations demonstrated that PU method inhibited the development of bacteria, mold, and yeast in freshly cut cucumber pieces at 4 °C. The PU-treated cucumber pieces exhibited a significant (p < 0.05) developments in bioactive components along with developed weight loss and firmness rather than other methods. In a similar way, PU-treated cucumber slices displayed the best colour parameters accompanying the smallest amount related to enzyme activity meaning lower browning enzymatically. Furthermore, the lowest scores in accordance with decay and off-odor values were determined in the freshly cut cucumbers subjected to PU. It is declared that PU method is an alternative technique to extend the storage conditions and keep the high-quality specifications in freshly cut cucumbers during cold storage.

High-Temperature Short-Time and Ultra-High-Temperature Processing of Juices, Nectars and Beverages: Influences on Enzyme, Microbial Inactivation and Retention of Bioactive Compounds

HTST (high-temperature short-time) pasteurization and UHT (ultra-high-temperature) sterilization are techniques commonly used in the dairy industry. Although the use of these methods in fruit and vegetable processing is also well known, the multitude of diverse food matrices determines the need to test and adjust process parameters in order to obtain the best quality of the final product. HTST and UHT are methods that provide effective inactivation of microorganisms and enzymes. Despite the fact that UHT and HTST are thermal processes that cause degradation of bioactive ingredients or color change, in many cases, these two methods are superior to traditional pasteurization, which uses significantly longer exposures to high temperatures. Therefore, this article aims to review the effect of HTST and UHT processing on the quality of juices, nectars and beverages, taking into consideration the quality characteristics, like the presence of microorganisms, pH, titratable acidity, total soluble solids, turbidity, color parameters, contents of bioactive components, antioxidant activity, enzymatic activity and volatile compounds. The impacts of HTST and UHT methods on various food products are discussed, including the food matrix, preservation parameters and the mechanism of interaction. The ability to modify the processing parameters can allow for the selection of adequate preservation parameters for individual products and better results than other unconventional methods, such as HPP (high-pressure processing) or PEF (pulsed electric field). Based on the cited literature, it can be concluded that pH, titratable acidity and TSS most often experience slight changes. As for the other parameters considered, it is extremely important to choose the right temperature and duration for a specific food matrix.

Vegetables Treated before Drying with Natural Antioxidants plus UV-C Improve Colour and Bioactive Compounds

The quality of minimally processed fruits and vegetables is essential for consumers’ health and effective marketing. This study investigates the effects of UV-C irradiation, applied alone and combined with various natural antioxidants, on the preservation of bioactive compounds and the colour of dehydrated fruits and vegetables. To achieve this, red peppers, yellow peppers, tomatoes, zucchini, eggplants, and melons were subjected to pre-treatments with natural antioxidants and UV-C before processing using low-temperature airflow (50 °C). The drying kinetics showed typical curves of hygroscopic materials, while the drying time was high due to the low temperature applied. The higher drying rate was found for eggplant, due to its porosity, thus allowing a faster moisture removal. The application of antioxidants and UV-C treatments effectively preserved the colour parameters L*, a*, and b*, while in the case of untreated dried vegetables, a significant worsening of colour parameters was noted. However, most applied pre-treatments had positive effects on bioactive compound losses. The best results were obtained using a combination of UV-C with one antioxidant mix that was composed of vanillin, rosemary, and citrus extracts, and combined with a mixture of olive, onion, garlic, and citric acid extracts, which was highly effective in preserving the colour and bioactive compounds of most dried vegetables.

Nutritional and functional synergism of Spirulina and açai mixtures in gummy candies

The compounds and properties of açai pulp and Spirulina biomass may suggest complementary and synergistic potential when combined. The aim of this work was to develop sucrose-free and dye-free gummy candies enriched with mixtures of freeze-dried açai pulp (FDAP) and Spirulina biomass. Four formulations were prepared: F1, 3% FDAP and 1% Spirulina; F2, 1% FDAP and 3% Spirulina; F3, 2% FDAP and 2% Spirulina and C, 0% FDAP and 0% Spirulina. The nutritional and functional contents, texture properties, color parameters and sensory characteristics of the gummy candies were assessed. Compared with the control, formulation F2 had the greatest increase in protein content (16.3%), whereas formulation F1 presented the greatest increase in lipid content (2.0%) and the greatest increase in total phenolic content (0.254 mg GAE g−1). Although the texture properties and the color parameters were significantly influenced (p < 0.05), the sensory evaluation showed a satisfactory acceptability index (AI) for the three formulations F1 (77.8%), F2 (82.8%), and F3 (80.1%). Thus, it was concluded that mixtures of Spirulina biomass and FDAP have a synergistic effect and could be combined as an innovative gummy candy formulation based on natural ingredients with incorporated bioactive compounds.Graphical

Optimization of novel sustainable Dictyota mertensii alginate films with beeswax using a simplex centroid mixture design

The environmental risks of synthetic polymers drive the need for innovative and sustainable film and packaging solutions. This study optimized the formulation of films composed of alginate derived from the brown seaweed Dictyota mertensii (ADM), glycerol, beeswax, and tween 80, aiming to improve their properties. A simplex-centroid blend design was employed to develop and optimize the composite films. The films were characterized based on their morphological properties, moisture content (MC), contact angle (CA), solubility (S), water vapor permeability (WVP), color parameters (L*, a*, and b*), opacity, tensile strength (TS), elongation at break (EB), and elastic modulus (E). Contour surfaces were plotted from the studied variables, fourth-order polynomial models were predicted, the influence of the blend components was analyzed, and the response variables were subjected to analysis of variance (ANOVA) and the F test with 95% confidence. The predicted conditions were experimentally validated. MC, WVP, solubility, opacity, a*, and b* were minimized, whereas CA, L*, TS, EB, and E were maximized, resulting in MC=6.85%, WVP=16.37 g.mm/h.kPa.m2, S=28.87%, CA=83.86°, Opacity=5.60 AU.nm.mm-1, L*=70.31, a*=4.79, b*=21.00, TS=11.76 MPa, EB=12.70%, and E=96.47 MPa. The overall desirability index was 0.70, resulting in an optimal biopolymer matrix of 75.00% ADM, 5.00% glycerol, 7.50% beeswax, and 12.50% Tween 80. The results highlight the potential of alginate films made from the brown seaweed Dictyota mertensii and the sustainable use of natural marine resources.

Innovative probiotic yogurt: Leveraging green banana peel for enhanced quality, functionality, and sensory attributes

Yogurt, a popular dairy product renowned for its nutritional benefits and probiotic content, serves as a functional food with potential health-promoting properties. The objective of this study was to investigate whether incorporating green banana peel polyphenol extract (GBPPE) into yogurt formulations enhances the viability and functionality of probiotics while also potentially improving the overall quality and health-promoting properties of the yogurts. GBPPE was extracted and added to the yogurt formulation at 0.0 %, 0.5 %, 1 %, and 2 %. Various physico-chemical properties of GBPPE as well as a range of physical, biochemical, sensory, and microbial assessments of formulated yogurts were carried out. Compared to the control, yogurt containing GBPPE improves functional characteristics by increasing antioxidant activity while having no detrimental impact on physicochemical and organoleptic properties. In terms of antioxidant capabilities, all fortified yogurts showed significantly (p < 0.05) higher total phenolic, flavonoid contents and antioxidant activities than the control yogurt. The addition of GBPPE also affected (p < 0.05) pH, titratable acidity, viscosity, water-binding capacity, syneresis, and total soluble solids, while no significant differences in the color parameters were detected in both control and all fortified yogurts with reduced brightness (L∗) and increased redness (a∗) of the product. The initial viable counts of all yogurt samples were almost similar, and the maximum and minimum viability loss of probiotics were observed in control and 2 % GBPPE fortified samples, respectively. Sensory assessment revealed that yogurt with 0.5 % banana peel extract outperformed all other treatments except the control. These findings support the sustainable use of GBPPE to create probiotic yogurt with improved physicochemical, microbiological, and sensory qualities.

Tannin-encapsulated electrospun nanofibrous membrane of cellulose nanowhiskers-reinforced polysulfone for colorimetric detection of iron(III)

A nanocomposite of tannic acid and cellulose nanowhiskers (CNW)-reinforced polysulfone (PSF) was used to develop a metallochromic nanofibrous membrane sensor for iron(III) in aqueous media. Tannic acid was used as an active detecting probe, whereas the CNW@PSF composite was employed as a hosting material. Cellulose nanowhiskers (7–12 nm) were obtained from microcrystalline cellulose (MCC). According to the coloration parameters, a bathochromic shift from colorless (415 nm) to purple (561 nm) occurs when ferric cations bind to the phenolic hydroxyls of the tannic acid probe. The concentration of ferric was found to be directly correlated to the extent of the color change, demonstrating a detection limit of 0.1–250 ppm. This could be attributed to the creation of a coordinative complex between ferric ions and phenolic tannic acid. The generated nanofibers were inspected by energy-dispersive X-ray (EDX) and scanning electron microscopy (SEM). The electrospun nanofibrous membrane showed an average diameter between 75 and 150 nm. The tannic acid-containing nanofibers are remarkably reusable and simple. The tannic acid-encapsulated polysulfone nanofibrous membrane was used to detect various metal ions, demonstrating a high selectivity for Fe3+. The ideal pH range for the identification of Fe3+ was determined to be in the range of 4.25–6.75.

Optimization of lycopene spray drying encapsulation in basil seed gum: Boosting bioavailability and mayonnaise stability

This study aimed to improve lycopene stability and bioavailability in food products. Lycopene, a potent antioxidant, often has poor stability and undesirable organoleptic properties. Therefore, the impact of basil seed gum (BSG) concentration and spray drying inlet temperature (IT) on the physicochemical, bioaccessibility, and antioxidant properties of encapsulated lycopene emulsion (ENL) was investigated using Central Composite Design (CCD)-Response Surface Methodology (RSM). Optimal encapsulation conditions were IT = 141.96 °C and BSG = 19.507 %. The ENLs had an average particle size of 147.56 nm, a polydispersity index (PI) of 0.263, and a zeta potential of −21.37 mV, indicating good colloidal stability. Antioxidant activity varied slightly during the four weeks of storage (a 9.65 % increase followed by a 13.6 % decrease), but it remained stable overall. Incorporating ENL into mayonnaise significantly reduced the acid value (2.78 mg KOH/g), the anisidine index (12.43), the peroxide value (7.13 meq/kg), and the TBARS index (0.534), and improved color parameters, reducing brightness (79.94) and whiteness (70.64) while masking lycopene's strong yellow and red hues. This study highlights BSG-encapsulated lycopene's potential to improve oxidative stability and sensory properties, offering a natural and effective method to enhance lycopene stability, bioavailability, and sensory acceptance in various food applications.

Early Chilling Injury Symptom Development and Recovery of Mature Green Banana: Involvement of Ethylene under Different Severities of Chilling Stress

The involvement of stress ethylene in early chilling injury (CI) symptom development of mature-green (MG) banana fruit was examined using the ethylene action inhibitor, 1-methyclopropene (1-MCP). MG banana fruit pretreated with 0 or 50 μg L−1 1-MCP were stored at two chilling temperatures, 5 °C or 10 °C, for 0, 1, 12, or 72 h (different CI stresses), then transferred to 20 °C (rewarming) for 2 d. Irreversible CI symptoms that developed during 72 h storage at 5 or 10 °C included vascular browning and epidermal color parameters (L*, chroma, and hue angle). Some CI symptoms drastically intensified during exposure to 5 or 10 °C for 72 h, even being exacerbated after rewarming. Fruit in the other treatments suffered milder CI, and the recovery response progressed from slight and reversible to severe and irreversible with longer durations of exposure to lower temperatures. The effect of 1-MCP pretreatment was to attenuate the effect of chilling in terms of the CI symptom development (i.e., the browning of sub-epidermal tissues and the increasing of electrolyte efflux) and to promote recovery after rewarming, especially for the fruit stored at 5 °C, indicating the potential involvement of ethylene in membrane structural alterations under CI stress.

Classification of Neoadjuvant Therapy Response in Patients With Colorectal Liver Metastases Using Contrast-Enhanced Ultrasound—With Histological Pathology as the Gold Standard

ObjectiveTo evaluate the response to neoadjuvant therapy in patients with colorectal liver metastases (CRLMs) using ultrasound(US) and contrast-enhanced ultrasound(CEUS), with correction to the tumor regression grade (TRG) of pathological results. MethodsThis study included patients with resectable CRLMs admitted from February to December 2022. After at least 4 cycles neoadjuvant therapy, all the patients received US and CEUS examinations within two weeks before hepatectomy. CEUS clips were postprocessed with color parameter imaging (CPI) and microflow imaging (MFI) analysis. Logistic regression analyses were used to develop an evaluation Nomogram. Ultrasound-based model was constructed to discriminate between the response (TRG1/2/3) and nonresponse (TRG4/5) groups at the lesion level. The model's predictive ability was evaluated using the C index and calibration curve, with decision curve analysis assessing the Nomogram's added value. ResultsThe study analyzed 105 CRLM lesions (the lesion with the highest diameter analyzed for each patient), with 43.8% showing a response to therapy. Univariate analysis identified calcification on US (p = 0.039), CEUS enhancement degree (p < 0.001), CEUS enhancement pattern (p<0.001), CEUS washout type (p < 0.001), CEUS necrosis (p < 0.001), CPI feeding artery (p = 0.003) and MFI pattern (p < 0.001) were significantly associated with TRG. The multivariate analysis showed CEUS enhancement pattern (p = 0.026), CEUS washout type (p = 0.018) and CEUS necrosis (p = 0.005) were independently associated with the neoadjuvant therapy response. A Nomogram with the three independent predictors was developed, with an AUC of 0.898. ConclusionThe ultrasound-based model provided accurate evaluation of pathological tumor response to preoperative chemotherapy in patients with CRLM, and may help to decide the individualized treatment strategy.

Replacement of native sugars of apples by isomaltulose in dual stages

The present study aimed to substitute the native sugars of apples for isomaltulose. In the first stage, native sugars were partially removed from the fruit tissue, and in the second stage, isomaltulose was incorporated. The use of ultrasound was evaluated at both process stages. Water loss (WL), solid gain (SG), water activity (aw), soluble solids content (°Brix), shrinkage (Sh), and color parameters (total color difference (ΔE), L* a*, b*, Cr*, and h°) were evaluated. The temperature of 35 °C stood out for its contribution to the mass transfer parameters (SG = 8.196%; WL = 21.699%—maximum values). There seems to be a threshold regarding the use of ultrasound in the process stages, indicating that its excessive use does not favor impregnation. The ideal process to promote the dehydration of apples and incorporation of the greatest amount of isomaltulose consisted of a treatment in which samples were immersed in water in the first stage, followed by impregnation of isomaltulose for 40 min assisted by ultrasound in the second stage. In addition, there was a significant reduction of aw (0.971 ± 0.001) and a slight change in color parameters (2.91 ± 0.45). Only concerning Sh (28.7 ± 3.6%), this treatment was not advantageous.Graphical

ALLEVIATIVE EFFECTS OF CHITOSAN AND NANOSILVER ON Solanum pimpinellifolium UNDER HEAVY METAL STRESS IN VITRO

This study aimed to investigate the potential mitigation of copper stress in tomato plants (Solanum pimpinellifolium L0566) through the addition of chitosan (CH) or nanosilver (nAg) to Murashige and Skoog (MS) medium under in vitro conditions. Various growth parameters; the proline, malondialdehyde (MDA), total polyphenol and mineral contents; and CIE L*a*b* colour parameters were evaluated. After the multiplication stage, the explants were transferred to MS medium (control); MS + 20 ppm chitosan with a molecular weight of 3.33 kDa (CH3.33); MS + 6 mg l–1 nAg; MS + 100 μM l–1 copper sulfate (CuSO4); MS+20 ppm CH3.33+100 μM l–1 CuSO4; or MS + 6 mg l–1 nAg + 100 μM l–1 CuSO4. The results indicated that while CuSO4 or CuSO4-nAg solutions inhibited growth traits, CH3.33 stimulated growth, particularly shoot production, and plants treated with CH3.33 exhibited better developed roots and a higher fresh mass. Additionally, CH3.33 alleviated the negative effects of CuSO4 on the proline, MDA and total polyphenol contents in tomato plants. Moreover, tomato explants exhibited greener leaves, while those treated with nAg and CuSO4 showed decreased colour values. CH3.33 or nAg positively influenced the mineral content of tomato leaves under heavy metal stress. This study underscores the complex interactions between growth medium components on tomato plant growth, physiology and the mineral content, highlighting the potential of chitosan in mitigating heavy metal stress in tomato plants.

RESPONSE OF THE ‘POLESIE’ RASPBERRY CULTIVAR TO FOLIAR APPLICATION OF CHITOSAN WITH DIFFERENT MOLECULAR WEIGHTS

This study explored the effects of chitosan, a biodegradable and non-toxic natural polymer derived from chitin, on the yield and quality of raspberries. Various molecular weights (3.3–950 kDa) were assessed to determine the impact on raspberry plants and fruit development. These applications were made during key growth phases – the start of the vegetation period, during flowering and at the fruit-bearing stage – using a foliar method to ensure full coverage of both leaves and fruit without runoff. The results indicated that chitosan application influenced various parameters of fruit quality, including firmness, colour and antioxidant levels. Notably, chitosan with a molecular weight of 21 and 50 kDa significantly enhanced fruit yield and size compared with the control. Conversely, chitosan with a higher molecular weight (500 and 950 kDa) did not improve yield and appeared to induce stress in plants, although they did contribute to increased fruit firmness and potentially extended the shelf life due to their film-forming capabilities. The findings suggest that while chitosan can improve the yield and quality of raspberries, the effectiveness is highly dependent on its molecular weight. These results support the potential of chitosan as an alternative to traditional chemical treatments, promising a reduction in chemical inputs while sustaining or enhancing agricultural productivity and fruit quality.

Physico-chemical properties and organoleptic acceptability of star fruit (Averrhoa bilimbi Linn.) jam with variations of natural sweeteners

Belimbing wuluh (Averrhoa bilimbi Linn.) is a fruit plant from Indonesia that has a very sour taste because it contains citric acid and oxalic acid. This sour taste is why this fruit has yet to be optimally utilized. This study aimed to determine the effect of natural sweetener variations on wuluh star fruit jam's physico-chemical and organoleptic properties. This study used an experimental method in which the experiment was designed in a completely randomized design (CRD) with 4 treatments and 3 repetitions. The results of this study showed that the addition of natural sweeteners to wuluh star fruit jam had a significant effect (p &lt; 0.05) on viscosity (9143 – 9450 mpa.s), sineresis (1.295 – 4.592 mg), vitamin C test (17.540 – 25.629 mg/100g), moisture content (23.57 – 31.19%), total sugar content (58.01 – 69.41%wb) and which had no significant effect (p&gt;0.05) on pH (3.38 – 3.64%). Meanwhile, organoleptic testing did not significantly affect taste, color, texture, aroma, and spreadability parameters. Keywords: Belimbing wuluh, Cassava sugar, Corn sugar, Honey, Jam

Enhanced Estimation of Crown-Level Leaf Dry Biomass of Ginkgo Saplings Based on Multi-Height UAV Imagery and Digital Aerial Photogrammetry Point Cloud Data

Ginkgo is a multi-purpose economic tree species that plays a significant role in human production and daily life. The dry biomass of leaves serves as an accurate key indicator of the growth status of Ginkgo saplings and represents a direct source of economic yield. Given the characteristics of flexibility and high operational efficiency, affordable unmanned aerial vehicles (UAVs) have been utilized for estimating aboveground biomass in plantations, but not specifically for estimating leaf biomass at the individual sapling level. Furthermore, previous studies have primarily focused on image metrics while neglecting the potential of digital aerial photogrammetry (DAP) point cloud metrics. This study aims to investigate the estimation of crown-level leaf biomass in 3-year-old Ginkgo saplings subjected to different nitrogen treatments, using a synergistic approach that combines both image metrics and DAP metrics derived from UAV RGB images captured at varying flight heights (30 m, 60 m, and 90 m). In this study, image metrics (including the color and texture feature parameters) and DAP point cloud metrics (encompassing crown-level structural parameters, height-related and density-related metrics) were extracted and evaluated for modeling leaf biomass. The results indicated that models that utilized both image metrics and point cloud metrics generally outperformed those relying solely on image metrics. Notably, the combination of image metrics obtained from the 60 m flight height with DAP metrics derived from the 30 m height significantly enhanced the overall modeling performance, especially when optimal metrics were selected through a backward elimination approach. Among the regression methods employed, Gaussian process regression (GPR) models exhibited superior performance (CV-R2 = 0.79, rRMSE = 25.22% for the best model), compared to Partial Least Squares Regression (PLSR) models. The common critical image metrics for both GPR and PLSR models were found to be related to chlorophyll (including G, B, and their normalized indices such as NGI and NBI), while key common structural parameters from the DAP metrics included height-related and crown-related features (specifically, tree height and crown width). This approach of integrating optimal image metrics with DAP metrics derived from multi-height UAV imagery shows great promise for estimating crown-level leaf biomass in Ginkgo saplings and potentially other tree crops.