Table 1
The results of the proximate parameters (Mean ± SD, n = 3) for white sugar products collected from Omo Kuraz factory in five different cycle of the years.
| white sugar sample type |
Parameters | Batch-2019 | Batch-2020 | Batch-2021 | Batch-2022 | Batch-2023 |
% Protein | 1.57 ± 0.23 | 1.45 ± 0.18 | 1.42 ± 0.16 | 1.25 ± 0.10 | 1.07 ± 0.07 |
% Fat | 1.25 ± 0.07 | 1.28 ± 0.02 | 1.74 ± 0.13 | 1.98 ± 0.06 | 2.08 ± 0.07 |
% Fiber | 0.231 ± 0.03 | 0.262 ± 0.01 | 0.281 ± 0.02 | 0.132 ± 0.02 | 0.244 ± 0.03 |
% Moisture | 0.750 ± 0.11 | 0.712 ± 0.13 | 0.363 ± 0.07 | 0.213 ± 0.03 | 0.184 ± 0.02 |
% Total solid | 99.3 ± 0.38 | 99.7 ± 0.28 | 99.3 ± 0.39 | 99.8 ± 0.35 | 99.8 ± 0.40 |
% Ash | 3.00 ± 0.55 | 3.33 ± 0.47 | 3.66 ± 0.32 | 4.00 ± 0.38 | 4.66 ± 0.55 |
%Carbohydrate | 93.2 ± 1.23 | 93.0 ± 0.69 | 92.5 ± 1.29 | 92.4 ± 1.09 | 91.7 ± 1.03 |
*Values are given as triplicate of Mean ± SD.
The results of the proximate composition (moisture, ash, fiber, crude protein, fat, carbohydrate content and total solid) for all the white sugar samples were presented in Table 1 expressed as mean ± SD for triplicate measurement of each samples.
Protein
The percentage range of protein content of sugar product samples as obtained in the current work was between 1.07 and 1.57%. The high protein values (1.57%) were found in the batch-2019 sugar product, while the lower protein values (1.07%) were found in the batch-2023 sugar product, suggesting that the refined white sugars have lower protein content than unrefined sugars [23]. There was a significant difference (p < 0.05) in the amount of protein analyzed from all five white sugar samples. The protein content of the current work is lower than the protein content reported by Hagos in Abyssinian purple wheat in Ethiopia (8.53%) [24] and agree agreed with the range of international standards (0.3–15%) [25] [26]. Passos et al. also reported a protein content of 3–11% in snack biscuits [4], which is significantly greater than the quantity of protein observed in the current investigation. The protein recommended daily intake established in the Netherlands were ranged between 8 and 11% [27]. Similarly, the accepted daily intake of proteins established in America and Canada was 9.1–13.5 g/day for infants, 13–19 g/day for children, and 34–71% for adults [28].
Fat
The results showed that among these species, Batch-2023 sugar product had the highest fat level (2.08%), while Batch-2019 sugar product had the lowest fat content (1.25%). Significant variation between the mean values of fat was observed among white sugar samples at (p < 0.05). Azlan et al. [23] has reported a lower value of 0.11%, 0.04% and 0.58% of fat in refined white sugar, minimally refined brown sugar and unrefined brown sugar, respectively. As shown in Table 1, the percentage value of fat content in the current study was lower than the findings of fat content established by national standards (3.03%) [24] and corresponded with the average range of fat content established by international standards (0.7–9.7%) [25]. The fat contents of five different batches of white sugar products in the current study were significantly lower than the results obtained from snack biscuits (cheese, fine herbs, salty, ham, and sesame) ranged from 17.3 to 23.2%, and sweet biscuits (chocolate, coconut, and malted milk) ranged from 17.2 to 19.0% were reported by Passos et al [4]. The recommended and optimal intake of fat contents set in Netherland was in the range of 20 to 40% [29].
Ash Content
The mean ash content of the tested samples varied from 3–4.66% (Table 1), indicating that the white sugar samples contain some nutritionally important minerals. Statistically, there is significant differences between white sugar samples in ash content (p > 0.05). Jaffe [30] reported that the ash content of sugar typically varied in the range of 0.3–3.6% which supports this study. A much lower ash content (0.01‒0.09%) was reported in refined white sugar and brown sugar samples [23]. The average percentage of ash content (3.0 to 4.3%) in snack biscuits and (1.8 ± 0.1 to 2.1 ± 0.1) in the sweet biscuits were reported by Passos et al. [4], agreed with the present study. High ash content is typically ascribed to a high potassium, calcium, and magnesium level which imparts an unpleasant taste to sugar and hinders its crystallization [31].
Fiber content
The crude fiber percentage range of white sugar products obtained in this study was between 0.132 and 0.281%. A one-way ANOVA test revealed a significant difference in fiber content between the analyzed white sugar samples from all five years (p < 0.05). The fiber content depends on processes used in juices extraction. These procedures tend to reduce and deteriorate natural fibers and other important ingredients [23]. The value of fiber observed in the present study was lower than the results reported by Azlan et al. [23] in brown sugar (2.38%) and minimally refined brown sugar (1.67%). Dietary fiber was (< 0.01%), reported as ND for (not detected), in refined what sugar in the same report. Fiber is essential for decreasing cholesterol, promoting the growth of healthy gut flora, treating diarrhea and constipation, and ensuring smooth digestive functioning [32] [33]. Fiber intake recommendations for children aged 19 to 25 g/day and adolescents aged 26 to 38 g/day were reported in the United States [34]. Furthermore, Kabir et al. [28] suggested the reference dietary intake of crude fiber content determined in America and Canada for children aged 19 to 25 g/day and adults aged 21 to 38 g/day.
Moisture Content
The results of moisture content of the analyzed sugar samples were ranged from of 0.184% (for batch-2023) to 0.750% (for batch-2019), Table 1. There was no significant difference in the moisture content among the five white sugar samples (p > 0.05). Moisture content of 0.1%, 0.15%, 0.11% for refined white sugar, brown sugar and minimally refined brown sugar was reported by Azlan et al. [23] which supports the present study. Lee et al. [31] has reported moisture content of commercial refined and non-centrifugal sugars in the range of 0.35‒4.4%, higher than the present study. Differences in the manufacturing processes might be the causes for the variation in moisture content among the sugar samples [30]. Moisture content of refined sugar is lower than unrefined sugar. Generally, high moisture content in sugar promotes the dissolution of crystals, cobblestone formation, microbial deterioration and biochemical degradation reactions, all of which shorten the shelf life of sugars [23]. Moisture in food is a good source of water and is necessary, as it is considered that around 20% of the total water consumption must come from food moisture [32].
Total Solid
The present study showed that the largest percentage of total solids (99.8%) was obtained from the Batch-2022 and Batch 2023 sugar product, while the smallest percentage of total solids (99.3%) was obtained from the Batch-2019 sugar product compared to other white sugar samples. There was a significant difference (p < 0.05) in the amount of total solids among the white sugar samples analyzed from the five different batches of the year.
Carbohydrate content: The results of this investigation demonstrated that the Batch-2020 sugar product had a greater carbohydrate content value (93.2%), whereas the Batch-2023 sugar product had a lower carbohydrate content value (91.7%). There was no significant difference in the carbohydrate content between analyzed white sugar samples obtained from the five different cycles of the year (p > 0.05). In contrast to other proximate values, refined sugar contains low to trace amounts of antioxidants and other nutrients besides sucrose. Carbohydrate content in the range of 96.8% (for brown sugar) to 99.81% (for refined white sugar) was reported by [23]. As can be seen in Table 1, the value of carbohydrate content in the present work was lower than the national standards (72.2%) [24] and agreed with the range of international standards (50.6–95.4%) [25]. The dietary daily intake of carbohydrate content established in Netherlands was between 45 and 65% [29]. Kabir et al [28] also reported the recommended daily intake of carbohydrate content set in America and Canada for Infant aged 60–95 g/day, for children aged 60 -95g /day and for adults aged less than 130 g/day.
Table 2
Results of toxic heavy metals (Cd and Pb) in white sugar products collected from Omo Kuraz Factory in different cycle of the years.
Analyte | White sugar samples (M ± SD, n = 3) (mg/kg) | |
Batch-2019 | Batch-2020 | Batch-2021 | Batch-2022 | Batch-2023 | Average (mg/kg) |
Cd | 0.217 ± 0.025 | 0.264 ± 0.035 | 0.433 ± 0.043 | 0.613 ± 0.030 | 0.617 ± 0.016 | 0.429 ± 0.031 |
Pb | 0.054 ± 0.004 | 0.169 ± 0.017 | 0.368 ± 0.010 | 0.380 ± 0.019 | 0.508 ± 0.013 | 0.296 ± 0.013 |
Cadmium
It is a nonessential element for the human body and is toxic to the kidneys, bones and cardiovascular system [35]. At high concentrations, cadmium produces serious effects on the liver and vascular and immune system [36]. For example, high level of Cd can cause high blood pressure, renal; failure, and can destroy tissues of the testicles and the erythrocytes. Cd can also cause demineralization of bones, impairment of lung function and vulnerability to lung cancer [37]. In comparison, the largest cadmium content level was recorded in the Batch 2023 sugar product, while the lowest concentration level was reported in the Batch 2019 sugar product. The average concentration level of cadmium in all white sugar samples was 0.429 ± 0.031 mg/kg in the present study. There is a significant difference in the content of Cd between the five sampling sites at p > 0.05. Cadmium level of less than 1 mg/kg was reported granulated crystal white sugar samples in India [1] and < 1 mg/kg in brown sugar samples in Brazil [38], which supports the present study. Ioannidou et al. [39] has reported cadmium concentration of less than 0.087 mg/kg in commercial sugar samples. Cadmium was associated with anthropogenic sources from phosphorus fertilization in sugar cane growing soil from Brazil [40]. According to the regulations of the Food Safety and Standards Authority in India, the maximum permissible level of cadmium in contaminated food is established at 1.5 ppm [41]. Likewise, the standard level of cadmium in contaminated food determined by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) is reported as 1 mg/kg [42]. Furthermore, the average quantity of lead in sugarcane investigated in Ghana is 2.1 µg/L [43], and the mean level of Pb in sugarcane soil recorded in China is 3.89 mg/Kg [44].
Lead
It is a non-essential trace metal element that constitutes a burden to organisms. It can cause a great danger to life that even in small quantities is lethal and has no known function in biochemical processes [37]. Pb exposure may have an adverse effect on the blood, nervous, immune, renal, skeletal, muscular, reproductive, and cardiovascular systems [36]. The highest amount of lead was found in the Batch-2023 sugar product (0.508 ± 0.013 mg/kg), and the lowest amount of lead was found in the Batch-2019 sugar product (0.054 ± 0.004 mg/kg). The average result of lead in all white sugar samples was 0.296 ± 0.013 mg/kg in this study. The one-way ANOVA test revealed a significant difference (p < 0.05) in variance in Pb concentration between the five sampling years. The level of lead in the current study exceeds the results of 0.045–0.060 mg/kg in white sugar reported in Turkey [45], whereas, it is much lower than the results of 94 ± 9 mg/kg in white sugar reported in Pakistan [33]. According to the Codex Alimentarius Commission's policy, specifically, the maximum Pb value that must be found in food is given as 1 mg/kg [46]. The standard level of lead in contaminated food determined by the joint FAO/WHO expert committee on food additives (JECFA) is reported as 2 mg/kg [42]. In addition to this, the average amount of lead in sugarcane studied in Ghana is 55 µg/L [43] and the mean concentration level of Pb in sugarcane soil reported in China is 8.16 mg/Kg [44]. Therefore, the results of the contaminant level of lead in the white sugar products of the current study were below the FAO/WHO safe limit.