Sweet orange [Citrus sinensis (L.) Osbeck] holds a prominent position within the Rutaceae family as one of the most commercially valuable citrus fruits grown across the globe (Saini et al., 2022). Though native to the tropical ecosystems of Southeast Asia, its cultivation has expanded extensively and it is currently grown on a commercial scale across more than 130 countries in both tropical and subtropical zones (Etebu and Nwauzoma, 2014). According to global agricultural data, worldwide production volumes crossed the 48 million tonnes mark during the 2021-2022 season, representing nearly 64% of the aggregate international citrus yield (FAO, 2022).
       
In the context of Indian agriculture, sweet orange orchards cover an estimated area of 5.8 lakh hectares, generating an annual crop yield of approximately 62 lakh metric tonnes. Looking at regional distributions within the country, the state of Maharashtra stands as the foremost producer, accounting for 1.54 lakh hectares under active cultivation and a total production output of 19.93 lakh metric tonnes (NHB, 2023).
       
Within the borders of Maharashtra, the cultivation of sweet oranges is largely clustered around specific agricultural belts, notably within the districts of Jalna, Aurangabad, Parbhani, Nanded, Nagpur, Amravati and Ahmednagar (MoAFW, 2023). Sector reports indicate that the Jalna district alone plays a disproportionately vital role in this state-wide supply chain, contributing close to 21% of the total fruit volume produced across Maharashtra (Directorate of Industries, 2024).
       
From a structural perspective, the anatomy of the fruit comprises three primary layers: a brightly colored exterior rind known as the flavedo, an internal spongy white tissue termed the albedo and an inner core filled with juicy pulp vesicles (Etebu and Nwauzoma, 2014). Processing observations show that the outer peel accounts for anywhere between 50% and 65% of the gross fruit weight, serving as a substantial byproduct that contains a dense concentration of various bioactive compounds.
       
From a nutritional standpoint, sweet oranges are highly favored by consumers due to their exceptional concentrations of health-promoting elements, including high levels of vitamin C, carotenoid pigments, complex dietary fibers and vital minerals such as potassium, calcium and magnesium (Virkar and Garande, 2023).
         
The external physical traits of the fruit heavily dictate its marketability and economic value (Jadhav et al., 2019), while the internal chemical profile governs consumer satisfaction and sensory preference (Shravan et al., 2018), which directly impacts product market longevity (Reddy et al., 2019) and limit structural post-harvest wastage through efficient value-addition parameters, such as the optimization of orange peel candy formulation using response surface methodology (Sidhanerlikar et al., 2026). Therefore , this systematic study was structured. The underlying purpose of this research was to conduct a comprehensive assessment of the physical characteristics, chemical composition, mineral profiles, objective color attributes, and industrial processing viability of sweet oranges harvested from the orchards of Parbhani, Maharashtra.

The present investigation was carried out at Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani during the academic year 2025-2026. Fully mature sweet orange [Citrus sinensis (L.) Osbeck] fruits displaying a uniform greenish-yellow rind color were purchased directly from a local wholesale market in Parbhani, Maharashtra, India. Upon arrival at the laboratory, the bulk samples were sorted manually to select healthy, unblemished fruits that exhibited consistent structural dimensions and physiological maturity.
       
The experimental process began with the evaluation of physical and  morphological traits. External features, which included the visual skin color, geometric shape, overall appearance and skin surface quality, were determined and recorded through direct physical examination. For the subsequent internal assessments, individual fruits were bisected cleanly along their equatorial axes using sharp stainless steel laboratory knives. All physical measurements were conducted using five independent batches, with five individual fruits evaluated per replicate, adhering strictly to the standardized analytical protocols described by Shravan et al., (2018).
       
The precise moisture content of the samples was calculated using a standard gravimetric hot-air oven drying method at 105°C, continuing the process until the sample reached an unchanging, constant weight (AOAC, 2000). The extracted fruit juice was then subjected to immediate chemical analysis, where the juice pH, total soluble solids content via refractometry (°Brix), titratable acidity percentage (%) in terms of anhydrous citric acid, total sugars and ascorbic acid concentrations were quantified using standard laboratory methodologies (Ranganna, 1986; AOAC, 1990). The complete proximate composition comprising total crude protein, fat content via ether extraction, total ash, crude fiber fractions and available carbohydrates calculated by mathematical difference was determined in accordance with the verified guidelines of the AACC (2000) and AOAC (2005).
       
For the elemental mineral profiling, the exact concentrations of Potassium (K), Calcium (Ca), Magnesium (Mg) and Iron (Fe) were measured via Atomic Absorption Spectrophotometry, following initial dry ashing and subsequent hot acid digestion procedures (AOAC, 2005). Objective color dimensions, including the lightness index (L*), the green-to-red axis (a*), the blue-to-yellow axis (b*), chroma and hue angle, were determined across the separated peel, internal pulp and fibrous segments using a digital colorimeter operating under the CIELAB color space framework (CIE, 1976). Finally, total juice recovery percentages, wet pomace weights and essential oil recovery rates were evaluated using standard citrus processing techniques (Hashmi et al., 2012). Every chemical test was executed in triplicate and all analytical results were statistically expressed as the mean value±standard deviation.

Visual characteristics of sweet orange fruit
 
The visual and morphological appearance parameters of the evaluated sweet orange fruits are systematically presented in Table 1. Visual inspection of the external and internal characteristics showed that the fruits possessed a characteristic greenish-yellow peel color, while the internal pulp segments displayed a highly appealing, uniform yellowish-orange hue. In terms of overall geometry, the fruits exhibited a distinct roundish-oval shape.


 
Physical and dimensional attributes of sweet orange fruit
 
The quantitative physical dimensions and mass evaluations of the fruits are systematically presented in Table 2. The values confirmed these structural metrics, where the average horizontal diameter was recorded at 69.09±1.38 mm and the vertical diameter was found to be 69.71±1.39 mm. Because these two perpendicular axes are nearly identical in length, the fruit maintains an exceptionally symmetrical profile, which is highly advantageous for commercial operations. Symmetrical fruits roll more uniformly on mechanized conveyor belts, allow for denser spatial arrangement during packing and reduce empty airspace in shipping crates.


       
The evaluations showed that the harvested sweet oranges had an average individual fruit weight of 196.56±3.93 g, which corresponds directly to a mean fruit volume of 155.24±3.10 mL. This weight-to-volume relationship indicates a high internal moisture content and structural density within the pulp matrix. Looking at the external protective barrier, the average peel thickness was measured at 2.08±0.04 mm, which worked in tandem with a physical fruit firmness value of 12.80±0.26 N. From a post-harvest physiology perspective, these two structural parameters serve as excellent indicators of the crop’s mechanical resilience. A peel thickness of over 2 mm combined with a firmness value of 12.80 N provides a sturdy natural cushion that shields the delicate internal tissue from localized compression stresses. This significantly limits the risk of impact bruising, structural deformation and subsequent microbial invasion during rough bulk handling, sorting, long-distance transport and shelf-life storage.
       
Internal anatomical dissection revealed a highly stable structural arrangement inside the citrus fruits. The internal carpellary structure was remarkably consistent, maintaining an average number of exactly 11.00±0.00 segments per individual fruit. Furthermore, the seed count analysis showed a mean value of 17.00±0.00 seeds embedded within the juicy pulp vesicles of each fruit. The absolute absence of variation (standard deviation of 0.00) in both segment and seed numbers underscores the high genetic purity and physiological uniformity of the sweet orange trees cultivated within this specific regional ecosystem. Collectively, these observed physical dimensions, visual traits and mechanical properties align closely with previously documented regional baselines recorded for sweet orange cultivars grown under the agro-climatic conditions of Maharashtra (Shravan et al., 2018).
 
Chemical composition of sweet orange juice
 
The chemical and proximate composition data of the sweet orange juice are systematically presented in Table 3. Analytical evaluations showed a high mean moisture content of 88.46±1.77%, which emphasizes the fruit’s excellent juiciness and hydration quality. The total soluble solids (TSS) stood at 11.45±0.23 °Brix, representing the major dissolved solids primarily soluble sugars and organic acids within the liquid matrix. The recorded juice pH was 3.59±0.07, indicating a moderately acidic profile, which works in tandem with a titratable acidity of 0.46±0.01% (calculated as citric acid). This precise balance between the TSS and organic acid content is a critical parameter that directly shapes the overall flavor profile, sensory acceptance and tartness preferred by consumers. 


       
From a nutritional standpoint, the juice revealed a substantial ascorbic acid (vitamin C) concentration of 46.50±0.93 mg/100 mL, confirming that the regional crop is an exceptional source of dietary antioxidants. The macronutrient profiling indicated a low crude fat level of 0.05±0.00%, a crude protein content of 0.70±0.01%, an ash content of 0.30±0.01% and a minimal crude fiber fraction of 0.11±0.00%. Total carbohydrates were found at a moderate level of 10.38±0.21%. The sugar breakdown detailed a reducing sugar content of 1.65±0.03% and a non-reducing sugar fraction of 6.02±0.12%, culminating in a total sugar value of 7.67±0.15%. These low lipid levels combined with moderate sugars confirm the juice’s commercial potential as a low-calorie, nutrient-dense natural beverage. All of these chemical and proximate observations align well with previous regional data published for sweet oranges in Maharashtra (Shravan et al., 2018). 
 
Mineral composition
 
The macro and micro-mineral profiles of the sweet orange samples are quantified and structured in Table 4. Elemental analysis revealed that potassium (K) was the most dominant mineral component present in the fruit tissue, registering a substantial concentration of 90.14±1.80 mg/100 g. Calcium (Ca) was identified as the second most abundant element, with a mean value of 37.98±0.76 mg/100 g. Additionally, the quantitative screening detected magnesium (Mg) levels at 8.90±0.18 mg/100 g, while the essential micro-mineral iron (Fe) was present at a baseline concentration of 0.30±0.01 mg/100 g. 


       
From a nutritional and physiological perspective, these specific elemental concentrations reflect a high dietary potential for the fresh produce. The high potassium-to-sodium ratio typical of citrus matrices, combined with these notable calcium and magnesium levels, highlights the fruit’s functional role in supporting metabolic electrolyte balances, fluid regulation and long-term bone health maintenance. These analytical mineral findings are highly consistent with previously documented dietary baselines established for sweet orange varieties (Oikeh et al., 2013). 
 
Colour profile of sweet orange components
 
The objective colorimetric parameters evaluated across the different anatomical parts of the sweet orange fruit are systematically organized in Table 5. Chromatic data obtained via the CIELAB color space indicated that the outer peel exhibited the highest lightness value (L* = 69.78±1.40) and a strong chroma value (C = 32.72±0.65). The negative green-to-red index value (a* = -0.41±0.01) combined with a substantial yellow axis value (b* = 32.16±0.64) and a high hue angle (h = 90.70±1.81) mathematically accounts for the vibrant, characteristic greenish-yellow surface appearance observed on the fruit’s exterior rind. These surface color findings are heavily governed by the degradation of chlorophyll and the simultaneous unmasking of underlying carotenoid streams during fruit ripening. This quantitative chromatic pattern tightly mirrors earlier observations recorded for Indian sweet orange rind matrices during post-harvest evaluation (Rokilu et al., 2022).


       
In comparison, the internal edible flesh displayed an L* value of 68.42±1.37 and a distinctly positive a* value of 6.90±0.14. This positive shift on the red-green axis reflects the underlying accumulation of natural lipophilic carotenoid pigments within the juice sacs. The edible flesh also showed a b* value of 25.56±0.51, a chroma value of 26.47±0.53 and a lower hue angle of 74.90±1.50, establishing a clean, visually appealing yellowish-orange profile. The significant increase in the a* value within the pulp structure relative to the rind indicates a deeper synthesis of beta-cryptoxanthin and related orange-hued pigments. This interior pigmentation behavior aligns perfectly with the standard internal color properties documented for citrus varieties cultivated in western regions of India (Shravan et al., 2018).
       
The structural fiber segments exhibited the lowest lightness profile (L* = 61.64±1.23) but registered the highest positive value on the red-green axis (a* = 9.22± 0.18), alongside a b* value of 26.68±0.53, a chroma value of 28.25±0.57 and a hue angle of 70.82±1.42. The reduced lightness values observed in the fiber or rag tissue point to a denser, light-absorbing cellulosic network, whereas the high positive red-green coordinate stems from vascular carotenoid distribution throughout the internal carpellary walls. These quantified color coordinate variances across the peel, flesh and fibrous tissue components offer crucial baseline metrics that heavily influence consumer visual perception and carry practical utility during the commercial grading and industrial sorting of the fresh produce (Vivek et al., 2025).
 
Processing characteristics
 
The manufacturing and processing yields obtained during the mechanical extraction of the sweet orange fruit samples are systematically compiled in Table 6. Quantitative laboratory assessments revealed that the primary target commodity, the juice yield, reached a mean recovery rate of 39.76±0.80%. The residual solid processing stream, or wet pomace, accounted for 32.58±0.65% of the total fruit mass. Furthermore, the extraction of the secondary high-value component from the rind yielded a volatile essential oil concentration of 3.02±0.06%.


       
From a commercial and industrial food processing perspective, these extraction metrics reveal strong economic potential for regional crop utilization. A juice recovery rate near 40% establishes a viable baseline for large-scale beverage manufacturing plants. Simultaneously, the substantial percentages of generated pomace and volatile peel oils should not be viewed merely as agricultural waste. Instead, these processing fractions represent highly lucrative opportunities for industrial by-product utilization, such as the extraction of essential oils for fragrances, cosmetic applications, or the recovery of dietary fibers and pectin from the pomace matrix. These observed technological extraction yields are in close agreement with standard processing baselines previously documented for sweet orange cultivars (Hashmi et al., 2012).

This study establishes the baseline physicochemical and processing profiles of sweet orange (Citrus sinensis L. Osbeck) in Parbhani, Maharashtra. The fruits exhibited high shape symmetry, structural firmness, and balanced TSS-to-acidity ratios. Nutritionally, the crop is dense in ascorbic acid, potassium, and calcium. Industrial trials confirmed excellent commercial viability, yielding 39.76% juice, 32.58% pomace, and 3.02% volatile essential oil. These findings provide crucial harvest benchmarks for growers and strategic value-addition parameters for regional agro-processing industries.

The authors are deeply grateful to the Department of Food Process Technology, College of Food Technology, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, for providing the necessary laboratory facilities, equipment and structural technical support to carry out this research work successfully.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
Not applicable. (The experimental protocols involved strictly botanical specimens [Citrus sinensis (L.) Osbeck] and did not involve any human subjects or live animal handling procedures requiring institutional animal care committee interventions).

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.