Rambutan Fruit Peel Research Articles

Nutrient Composition and Antioxidant Potential of Rambutan (Nephelium lappaceum L) Peel

The present study was conducted to assess the nutri-chemical composition and antioxidant potential of rambutan fruit (Nephelium lappaceum L) peel. Red rambutan fruit peel was used in fresh as well as dried form for the study. The nutri-chemical profiling revealed, fresh peel had 24g/100g of carbohydrate, 2.5g/100g of protein, 0.17g/100 g of fat and 0.89g/100g starch. However, dried peel had 55.45g/100g carbohydrate, 5.25g/100 protein, 10.2g/100g fat and 1.00g/100g starch. Crude fiber content of the fresh and dried peel was 0.77g/100g and 0.068g/100g respectively. Moreover, the fresh peel had higher moisture (73%) content than dried peel (4.2%). Vitamin C being heat liable, was found higher in fresh peel (9.31mg/100g). Sodium and potassium levels was found higher in dried peel powder as 1.55mg/100g and 9.4mg/100g respectively. Phytochemical composition of rambutan peel revealed that total polyphenol was higher in dried peel (580mg/100g) when compared to fresh (310 mg/100 g), meanwhile saponin, tannin and terpenoid was found higher in fresh peel as 47mg/100g, 390mg/100g and 5.101mg/100g respectively. Flavonoid content was dominant in dried peel (20.51mg/100g) than that of fresh peel (9.6mg/100 g). The radical-scavenging activity was expressed as IC50, which reported dried peel (43.79μg/100 mL) had strong antioxidant potential than fresh peel (184.39μg/100mL). However, it is concluded that rambutan peel is a potent source of nutrients, bioactive compounds and antioxidants which in turn has immense therapeutic benefits. Furthermore, valorisation of agri-food wastes and by- products can enhance food security and promote sustainable development.

Improve the Effectiveness of Inhibiting Pathogenic Fungus and Maintaining the Quality of Rambutan (Nephelium lappaceum L.) Post-Harvest by Indigenous Lactic Bacteria

The change in the quality of rambutan (Nephelium lappaceum L.) fruit after harvest is mainly dehydration. Rambutan fruit peel is often dark (brown) and fruit rot due to fungal disease. This study investigated the effects of Lactobacillus bacteria strains [Lactobacillus plantarum CC6 (CC6), Lactobacillus fermentum DC2 (DC2), Lactobacillus fermentum DGMC2 (DGMC2)] with/without supplement combinations [chitosan 0.03% (Chito), alginate 0.03% (SA) and carboxymethyl cellulose 0.5% (CMC)] on the quality of Java rambutan fruit during storage at 13 °C, and included a sample without treatment with bacteria and chemical considered as the control. The results showed that among 16 treatments on rambutan fruits immediately after harvesting, the four treatments that showed the best results were CC6-Chito, DC2-Chito, CC6-CMC and DC2–SA, and DC2-Chito was more effective than the others. However, all four of these treatments supported the preservation of rambutan fruit, reducing both weight loss and browning of the skin and stem, and kept the infection rate at the lowest level. The brightness and peel color values were highest for these treatments.

Comparative Metabolomic and Transcriptomic Analysis Reveals That Variations in Flavonoids Determine the Colors of Different Rambutan Cultivars

Rambutan is a tropical tree and its fruit has several favorable characteristics. To understand how the color of the rambutan fruit peel develops, the transcriptome, flavonoid metabolome, and carotenoid metabolome data of two rambutan cultivars, ‘BY2’ and ‘BY7’, which show yellow and red peels at maturity, respectively, were comprehensively analyzed at three developmental stages. We identified 26 carotenoid components and 53 flavonoid components in these cultivars. Anthocyanins were the main component contributing to the red color of ‘BY7’ after reaching ripeness. The carotenoid content decreased sharply as the fruit matured. Hence, we speculated that flavonols were the main contributors to the yellow color of the ‘BY2’ peel. In total, 6805 differentially expressed genes were screened by transcriptome analysis; the majority of them were enriched in metabolic pathways and the biosynthesis of secondary metabolites. Weighted gene co-expression network analysis results revealed that in addition to MYB and bHLH, ERF, WRKY, MYB-related, and C3H were the main potential transcription factors regulating the color of the rambutan peel. In addition, we also identified 12 structural genes associated with flavonoid biosynthesis. The research findings shed light on the molecular mechanisms of color acquisition in rambutan fruit peels, laying the foundation for the quality control of rambutan and the cultivation of differently colored cultivars of rambutan.

Rambutan Fruit Peel Extract Reduces Abnormal Sperm Morphology in Male Wistar Rats with Obesity

AbstractObesity is an accumulation of excessive fat tissue in the body. Excessive fat tissue in the body lead to infertility by increased Reactive Oxygen Species (ROS) and decrease the hormone balance regulation, those things can be affected the process of spermatogenesis, especially sperm morphology. Rambutan peel was known as a source of antioxidants because it has phenolic compounds, so it has a protective effect on free radicals. The research purpose knew the effect of Rambutan Peel Extract (RPE) (Nephelium lappaceum) on abnormal sperm morphology of Wistar rats (Rattus novergicus) percentage induced with a High-Fat Diet (HFD). This study uses True experimental post control group design for this research on 30 male Wistar rats. Samples were divided into 5 groups. Group 1: induced HFD only, Group 2: only given RPE at a dosage of 30 mg/kilogram Body Weight (kg BW), Group 3, 4, and 5: induced HFD and RPE at dosage of 15 mg/kg BW, 30 mg/kg BW, and 60 mg/kg BW feed using sonde. The data were analysed using ANOVA One Way. The result showed that RPE has decreased the abnormal sperm morphology of male Wistar rats at dose of 15 mg/kg BW. This is the first study that observe the effect of RPE administration to sperm morphology of obese and non-obese group of rats, with larger rats’ population, several doses of the RPE extract, and longer time to complete one cycle of rat spermatogenesis.AbstrakObesitas diartikan sebagai akumulasi jaringan lemak berlebihan yang ada di dalam tubuh. Jaringan lemak yang berlebihan dapat menyebabkan ketidakseimbangan regulasi hormonal dan terbentuknya Reactive Oxygen Species (ROS). Kedua hal tersebut dapat mempengaruhi proses spermatogenesis sehingga dapat menyebabkan infertilitas, terutama pada morfologi sperma. Ekstrak Kulit Rambutan (EKR) diketahui memiliki efek sebagai antioksidan dikarenakan memiliki senyawa fenolik, senyawa tersebut dapat menangkal radikal bebas. Penelitian ini dilakukan untuk mengetahui pengaruh pemberian EKR (Nephelium lappaceum) terhadap persentase morfologi abnormal sperma tikus Wistar (Rattus novergicus) yang diinduksi dengan Pakan Tinggi Lemak (PTL). Penelitian ini menggunakan desain True experimental post control group design pada 30 ekor tikus. Sampel dibagi menjadi 5 kelompok. Kelompok 1: hanya diberi PTL, Kelompok 2: hanya diberikan EKR dengan dosis 30 mg/kilogram Berat Badan (kgBB), Kelompok 3, 4 dan 5: diinduksi dengan PTL dan EKR dengan dosis 15 mg/kgBB, 30 mg/kgBB, dan 60 mg/kgBB. Pemberian PTL dan EKR dilakukan menggunakan sonde. Data dianalisis menggunakan uji ANOVA One Way. Hasil penelitian menunjukkan bahwa EKR dapat menurunkan jumlah morfologi abnormal pada kelompok dengan induksi PLT, dengan dosis yang paling efektif 15 mg/kgBB. Studi ini adalah yang pertama dalam mencari tahu efek pemberian RPE tehadap morfologi spermatozoa pada kelompok tikus obesitas dan tidak obesitas, dengan populasi tikus yang lebih besar, beberapa dosis ekstrak RPE, dan waktu yang lebih lama agar dapat menyelesaikan satu siklus spermatogenesis tikus.

The potential of rhizobacteria for use of rambutan (Nephelium lappaceum) peel as organic fertilizer

Rambutan (Nephelium lappaceum) production is growing worldwide so the treatment and utilization of Rambutan by-products has become a concern of manufacturers. The objective of this study was to evaluate the potential application of rhizobacteria to decompose Rambutan peel for organic fertilizer production. After the rhizospheric soil samples were selectively proliferated and preadded on agar medium containing only Rambutan peel, the rhizobacterial colony isolates were screened based on their ability to grow on this agar medium and then to degrade cellulose in Rambutan peel. The LD7.3 isolate from the Rambutan rhizosphere showed the highest efficiency in degrading Rambutan peel with 5.6% degraded cellulose content and was identified by the MALDI-TOF technique as belonging to Klebsiella. Klebsiella sp. LD7.3 grew well and maintained the same degrading activity after three times of subculturing in liquid medium. Notably, the supplementation of grinded Rambutan fruit peel to the liquid medium had a positive effect on the growth and the degrading activity of Klebsiella sp. LD7.3. This was the primary report on the application of rhizobacteria to degrade Rambutan peel and the results showed that this was a potential approach to reuse this waste source.

Enhancing Rumen Fermentation Characteristic and Methane Mitigation Using Phytonutrient Pellet in Beef Cattle

The objective of this experiment was to assess the effects of chaya (Cnidoscolus aconitifolius) leaf and rambutan (Nephelium lappaceum L.) fruit peel pellet (CRP) supplementation on rumen fermentation, feed intake, nutrient digestibility, and nitrogen balance in crossbred beef cattle. Four beef cattle crossbred bulls (Brahman 75% × Thai native 25%), with 250 ± 15 kg of liveweight at 18 months old, were randomly selected to receive four dietary treatment groups: no supplementation (control) and the supplementation of CRP at 2, 4 and 6% of dry matter intake (DMI) by using a 4 × 4 Latin square design. The cattle were fed a concentrate at 2 kg/day, and rice straw was offered ad libitum. The results showed that rumen pH at 4 h and average post-feeding values were in the normal range, though they were slightly reduced with CRP supplementation at 4 and 6% DMI (p < 0.05). Rumen temperature, ammonia nitrogen level, and total volatile fatty acid (VFA), acetate (C2), and butyrate (C4) production were similar among treatments. Nevertheless, propionate (C3) concentration was significantly increased (p < 0.05) in the CRP groups at 2 and 4% DMI. In addition, the C2/C3 ratio and CH4 production were significantly reduced in the CRP groups, especially at 2 and 4% DMI. Rice straw intake and total feed intake in terms of %BW were significantly higher in the groups with CRP at 2 and 4% DMI (p < 0.05). The apparent nutrient digestibilities were not affected by the treatments. Nitrogen intake, nitrogen absorption, and nitrogen retention were significantly enhanced by the CRP supplementation (p < 0.05). Moreover, feces and total nitrogen excretion were not different among treatments (p > 0.05). Ultimately, the supplementation of CRP at 2 and 4% DMI significantly improved the C3 concentration, reduced the C2/C3 ratio, mitigated methane production, and enhanced feed intake and nitrogen utilization efficiency. Therefore, CRP supplementation shows promise as a rumen dietary enhancer.

Nephelium lappaceum Extract as an Organic Inhibitor to Control the Corrosion of Carbon Steel Weldment in the Acidic Environment

Organic inhibitors have been considered as an effective way to control the corrosion of carbon steel weldment in an acidic environment. This work proposes a new green organic inhibitor made of extract of rambutan fruit (Nephelium lappaceum) peel and aims at analyzing its corrosion inhibitor properties and protection mechanism. Specimens of carbon steel weldment were tested for their corrosion by using electrochemical and immersion methods in 1 M HCl solution containing 0 to 6 g/L of Nephelium peel (NP) extract. Results showed that, in the same solution, the corrosion rate was measured to be higher on the weld metal zone than that of base metal zone, which could be related to the coarser grain of the weld metal zone and the stability of the formed oxide layer. The addition of NP extract was found to increase the stability of the oxide layer, thus increasing the corrosion resistance of the specimens. The maximum inhibition efficiency of the NP extract was reached at 97% for weld metal with 5 g/L of extract, at 80% for the heat affected zone with 5 g/L, and at 70% for base metal with 4 g/L. This work reveals the particularity of different weldment zones to the different needs of inhibitor concentration for obtaining the optimum corrosion protection.

Mitigating rumen methane and enhancing fermentation using rambutan fruit peel powder and urea in lactating dairy cows.

The experiment was designed to study the use of rambutan (Nephelium lappaceum) fruit peel powder (RP) with urea (U) supplementation on rumen fermentation, digestibility, methane (CH4 ) production, milk production and composition in lactating dairy cows. Four Holstein crossbred lactating dairy cows, with starting liveweight of 450±15kg with 130±10 DIM (days-in-milk), were randomly allocated to respective treatments: without supplementation (control; T1), supplementation of urea (U) at 90g/hd/day (T2), supplementation of RP at 450g/hd/day (T3) and supplementation of RPU (RP at 450g/hd/day and U 90g/hd/day) (T4), respectively, using a 4×4 Latin square design. The results showed that the U, RP and RPU supplementation did not change feed intakes (p>0.05) and digestibilities of DM and OM were similar. However, digestibilities of CP and NDF were increased in the U and RPU groups (p<0.05). Acetate production was decreased, while propionate production was dramatically increased (p<0.05) in both the RP and RPU groups respectively. Notably, the ratio of C2 :C3 , protozoal population and CH4 production was reduced in both the RP and RPU groups. In addition, nitrogen intake and nitrogen excretion were significantly higher while nitrogen retention was increased in the U and RPU groups. Allantoin excretion and absorption, microbial protein synthesis and efficiency of microbial N supply were increased in the U and RPU supplementation groups (p<0.05). Furthermore, milk yield, milk fat and total solids were significantly enhanced in the U and RPU groups (p<0.05). Moreover, the 3.5% FCM was increased (p<0.05) while milk protein, lactose, solids-not-fat and milk urea nitrogen were not altered (p>0.05). Supplementation of either U or RPU significantly improved fibre digestibilities, rumen fermentation, microbial protein synthesis, reduced protozoal population, mitigated CH4 production and enhanced milk yield and milk composition.

Biomedical application of single anatase phase TiO2 nanoparticles with addition of Rambutan (Nephelium lappaceum L.) fruit peel extract

Metal oxide nanoparticles are considered to be an important material due to their good mechanical stability, unique structure and catalytic properties. The hydrothermal method was followed along with rambutan (Nephelium lappaceum L.) fruit peel extract mixed with metal ions to prepare titanium dioxide (TiO2) nanorods. Though there are numerous similar works published in past decades, in comparison with those works, the novelty of this work is using rambutan fruit peel as a precipitation agent. The advantages of using such natural agents are that they are eco-friendly and economically feasible. The prepared TiO2 nanorods were co-cultured with human breast cancer cells (MDA-MB-231) and their cytotoxicity was evaluated. The morphology of the nanorods was analyzed through transmission electron microscopy. The average diameter of the TiO2 nanorods was found to be 70–90 nm. The anatase phase of the tetragonal structure was confirmed through X-ray diffraction analysis. The studies of the vibrational Raman active modes and optical properties confirmed the presence of TiO2. X-ray photoelectron spectroscopy binding energy of Ti2p3/2 determined as 460 eV and that of O1s determined as 532 eV confirmed the presence of TiO2. Cytotoxicity was analyzed using MDA-MB-231 and cell death was observed at 73.65 µg/ml.

Studi Kinetika Adsorpsi Cu(II) Dan Pb(II) dengan Menggunakan Biosorben dari Polimer Ekstrak Kulit Buah Rambutan

Recovery Cu(II) dan Pb(II) yang sebagian besar terkandung dalam limbah cair industri, baik industri besar maupun rumah tangga telah dilakukan, salah satunya adalah dengan proses adsorpsi. Penelitian ini dilakukan studi kinetika adsorpsi Cu(II) dan Pb(II) dalam limbah cair untuk mengetahui efektivitas biosorben dari ekstrak kulit buah rambutan terhadap limbah cair yang mengandung Cu(II) dan Pb(II). Penentuan kinetika adsorpsi Cu(II) dan Pb(II) dengan menggunakan biosorben dari ekstrak kulit buah rambutan dilakukan melalui beberapa model kinetika yaitu model kinetika Langmuir-Hinshelwood, Santosa, Lagergreen dan Ho. Kinetika adsorpsi Cu(II) dan Pb(II) semuanya mengikuti model kinetika Ho, yang merupakan mekanisme kinetika orde dua semu.

Effect of Rambutan Fruit Peel Extract on Total Sperm Counts of Wistar Rats With Obesity

Obesity caused by a high-fat diet leads to an altered reproductive hormonal profile, including impaired semen quality. Antioxidants can overcome these conditions. One of the well-known sources of antioxidants is in the rambutan fruit peel extract. This research aimed to figure the effect of rambutan fruit peel extract towards total sperm count in Wistar rats induced with high-fat feed. The study design used post-test only control group, subjects were 30 male Wistar rats divided into five groups: Group I (Positive Control) was given high-fat feed, Group II (Treatment Control Group) was given 15mg/kg BW rambutan fruit peel extract, whereas group III, IV, V (Treatment Group) were given an extract of rambutan skin with a dosage of 15, 30, and 60 mg/kg BW, respectively. Treatment was administered for 81 days. This study showed that rambutan fruit peel extract with doses of 15, 30, and 60 mg/kg BW has significantly increased total sperm count in Wistar rats induced with high-fat feed. The outcome using Kruskal Wallis shows a result of p-value 0,010 (CI 95%). Antioxidant compounds found in rambutan fruit peel extract significantly increase total sperm count in Wistar rats induced with high-fat feed, with the highest efficacy on the dose of 15mg/kg BW.&#x0D; &#x0D; Keywords: Fruit Peel Rambutan Extract; ; ;

Selection of extraction conditions of phenolic compounds from rambutan (Nephelium lappaceum L.) peel

The objectives of this study focused on optimizing extraction conditions (i.e. type of solvent (methanol, ethanol, and water) and their concentration, temperature, time, and the effect of ultrasound-assisted extraction (UAE)) for extracting phenolic compounds of rambutan fruit peel. Furthermore, a procedure to prepare crude phenolic powder from rambutan peel was suggested. Total phenolic content and antioxidant properties of rambutan peel extracts were examined using spectrophotometric methods. Solid phase extraction and high-performance liquid chromatography were used for identifying phenolic compositions in rambutan peel extracts. Methanol 80% had significant effects to obtain higher extraction yields of phenolic compounds. UAE significantly affected the yield of phenolics of rambutan peel with an increase in phenolic content of 15% compared to methanolic extraction (without ultrasound application). Phenolic compounds such as geraniin, corilagin, rutin, ellagic acid, and quercetin were predominant in rambutan peel extracts. An extraction procedure was summed up to obtain 55−64 g of lyophilized powder from 1 kg of fresh rambutan peel. The total phenolic content in this crude phenolic powder was 250−300 mg GAE/g. Its antioxidant activity (at 100 μg GAE/mL) was much higher than those of tert-butylhydroquinone, l-ascorbic acid, α-tocopherol, and ethylenediaminetetraacetic acid (at 100 μg/mL).

Evaluation of antimicrobial activity of rambutan (Nephelium lappaceum L.) peel extracts

Microbial safety in food products is not always adequately controlled. Chemical antimicrobials which are recognized as hazards to human health are gradually replaced by natural antimicrobial compounds. In the current study, the antimicrobial activity against some Gram-positive and Gram- negative bacteria by the methanolic extract from rambutan fruit peels was evaluated using both in vitro (medium) and in situ (food matrices i.e. raw chicken breast and pangasius fillet fish) methods. Methanolic rambutan peel extract (lyophilized to powder with total phenolic content of 310 ± 14.5 mg GAE/g) with geraniin, ellagic acid, rutin, quercetin, and corilagin as main phenolic compounds was a potent inhibitor towards E. coli, V. campbellii, V. parahaemolyticus, V. anguillarum, P. aeruginosa, S. enteritidis, St. aureus, L. monocytogenes, and C. albicans using in vitro tests. In in situ tests, the extract inhibited S. enteritidis in raw chicken breast during 14 days of cold storage at 4 °C. Even though food matrices partly protected bacteria, the extract showed a 1.5 log CFU/g reduction of V. parahaemolyticus in fish during 10 days of cold storage. These results provide useful information on the utilization of rambutan fruit peel as natural antimicrobial agent in food products.

Antioxidant Activity of Rambutan (Nephelium lappaceum L.) Peel Extract in Soybean Oil during Storage and Deep Frying

AbstractRambutan (Nephelium lappaceum L.) peel (RBP) is discarded as the main by‐product during processing of the fruit. Increasing attention is now paid to the valorization of RBP for the recovery of valuable compounds. Geraniin, ellagic acid, quercetin, and rutin are the main phenolic compounds found in methanolic RBP extract. Extracted rambutan peel powder (ERPP) is used to evaluate the oxidative stability of soybean oil stored at 4 and 30 °C in the dark and light and deep fried with potatoes at 160 °C. Tert‐butylhydroquinone (100 µg g−1 oil, TBHQ) serves as positive control. Oil supplemented with ERPP of 1000 µg gallic acid equivalents (GAE) g−1 of oil shows positive effects on the retardation of the oxidation process during storage in comparison with oil without addition. During deep frying, either ERPP (1000 µg GAE g−1) or TBHQ retards the lipid oxidation of oil. Levels of thiobarbituric acid reactive substances of potatoes fried in oil fortified with the extract and TBHQ (0.4–0.59 µg g−1) are much lower than those without the extract (1.31 ± 0.10 µg g−1) (p &lt; 0.05). Therefore, RBP extract exhibits favorable antioxidant effects and can be used for effectively inhibiting lipid oxidation in oil during storage and deep frying.Practical Applications: An extract from rambutan fruit peel containing phenolic compounds, that is, geraniin, ellagic acid, rutin, and quercetin showed promising results to be used as potential antioxidants in soybean oil during deep frying. Both oxidation of the frying oil as well as the oxidation of the food product, that is, potatoes were inhibited. These results demonstrated that rambutan fruit peel extract can be used as a natural antioxidant in frying oil to replace synthetic antioxidants, that is, TBHQ.

Dietary rambutan peel powder as a rumen modifier in beef cattle.

ObjectiveThe experiment was conducted to study the effect of rambutan (Nephelium lappaceum) fruit peel powder (RP) on feed consumption, digestibility of nutrients, ruminal fermentation dynamics and microbial population in Thai breed cattle.MethodsFour, 2-year old (250±15 kg) beef bull crossbreds (75% Brahman×25% local breed) were allotted to experimental treatments using a 4×4 Latin square design. Four dietary supplementation treatments were imposed; non-supplementation (control, T1); supplementation of RP fed at 2% of dry matter intake (DMI) (low, T2); supplementation of RP fed at 4% of DMI (medium, T3) and supplementation of RP fed at 6% of DMI (high, T4). All cattle were given a concentrate supplement at 1% of body weight while Napier grass was provided as a free choice.ResultsThe findings revealed that RP supplementation did not negatively affect (p>0.05) DMI of Napier grass, while RP intake and total DMI were the greatest in the RP supplementation at 4% and 6% DMI. Nevertheless, the nutrients (dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber) digestibilities were not changed in the RP supplementation groups. Rumen fermentation parameters especially those of total volatile fatty acids, acetate and butyrate were not significantly changed. However, the propionate concentration was remarkably increased (p<0.05) in the RP supplementation. Notably, the ratio of acetate to propionate, the number of protozoa, as well as the methane estimation were significantly reduced in the RP supplemented groups (4% and 6% of DMI), while the counts of bacteria was not altered.ConclusionSupplementation of RP (4% of DMI) improved rumen propionate production, reduced protozoal population and methane estimation (p<0.05) without a negative effect on feed consumption and nutrients total tract digestibilities in beef cattle. Using dietary rambutan fruit peel powder has potential promise as a rumen regulator.

Rambutan fruit peel powder and dietary protein level influencing on fermentation characteristics, nutrient digestibility, ruminal microorganisms and gas production using in vitro fermentation techniques.

The objective of this study was to evaluate the effect of rambutan (Nephelium lappaceum) fruit peel powder (RP) on fermentation characteristics, rumen microorganisms, and in vitro gas production. Three levels of crude protein (CP) in the concentrate (14%, 16%, and 18% CP) and supplementation of rambutan peel powder (0, 2, 4, and 6% of the total dietary substrate) were designed for treatments according to 3 × 4 factorial arrangement in a completely randomized design (CRD). The rumen fluid samples were collected from two-fistulated dairy bulls which had been fed on rice straw with concentrate to adjust the rumen environment. The ratio of roughage (R) and concentrate (C) at 60:40 was used, and all ingredients were added according to the mentioned ratio, respectively. Under this study, supplementation of CP at different levels in the concentrate diet significantly altered (P < 0.05) rumen NH3-N at 6 and after 12h of incubation, whereas the rumen pH was not significantly changed with CP and RP supplementation levels at any times of incubation. The rumen pH was declined at 18% CP at 6h of incubation time, as compared to 14 and 16% CP with 0% RP supplementation. The CP and RP supplementation could enhance and maintain the rumen pH during incubation to the optimum condition. The RP supplementation significantly doubled bacterial population while reduced protozoal population; however, fungal zoospores were not altered with CP and RP supplementation. The ruminal propionate (C3) production was remarkably higher (P < 0.05) by the RP and CP supplementation. The ratio of acetate to propionate (C2:C3) was decreased (P < 0.05) with RP supplementation. Meanwhile, rumen methane (CH4) production was significantly reduced by the RP supplementation. In addition, high level of RP supplementation (6% of total substrate) also significantly decreased the cumulative gas production and the in vitro true digestibility (%IVTDMD). Level of CP had no effect on rumen fermentation while interactive effects of CP level and RP supplementation were not found. This current study indicated that RP supplementation could suppress protozoal population, mitigate methane production, and improve rumen fermentation.

Nutritional and therapeutic potentials of rambutan fruit (Nephelium lappaceum L.) and the by-products: a review

The progressive development of functional foods and herbal medicine has enthused many researchers to explore novel plant sources. In this regard, the rambutan fruit (Nephelium lappaceum L.) appears to be a promising candidate primarily due to its nutritional and bioactive compositions. With that, this particular review presents a systematic depiction of chemical composition and bioactivities of the rambutan fruit peel, pulp, and seed. Numerous reports do not provide sufficient data pertaining to cultivar, stage of maturity or the environment of fruit, yet the summarized data suggest a myriad of therapeutic potentials derived from the rambutan fruit. In fact, the rambutan fruit has been proven to possess phytochemicals that demonstrate anticancer, anti-allergic, anti-obesity, antidiabetic, anti-HIV, antimicrobial, anti-dengue, anti-hypercholesterolemic, and antihyperglycemic effects in varied in-vitro and in-vivo models. Nonetheless, advance studies are indispensable to further highlight the therapeutic mechanisms involved. In addition, a phytochemical analysis would further establish the rambutan fruit as a sustainable candidate in developing functional foods and pharmaceuticals.

GEL NANOEMULSION OF RAMBUTAN (NEPHELIUM LAPPACEUM L.) FRUIT PEEL EXTRACTS: FORMULATION, PHYSICAL PROPERTIES, SUNSCREEN PROTECTING, AND ANTIOXIDANT ACTIVITY

Objective: The aim of this study is to determine the optimum formulation of gel nanoemulsion of the rambutan fruit peel extracts (RFPEs), sunscreen protecting factor, and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric thiocyanate (FTC) methods.Materials and Methods: Formulation was optimized based on the variety of concentrations of RFPE, namely, 0.25%; 0.38%; 0.51%; and 0.63%. Gel nanoemulsion was characterized based on a number of the physical and chemical properties, such as pH, viscosity, adhesion, spread property, stability, and particle size. Sunscreen protecting factor and antioxidant activity were conducted using spectrophotometer ultraviolet-visible.Results: The result showed that the particle size of gel nanoemulsion formulation 1 (FI), FII, FIII, and FIV were at 13.30±4.00 nm, 1.90±9.70 nm, 2.70±13.60 nm, and 14.50±2.50 nm, respectively. Based on transmission electron microscopy image, it showed that formula with the concentration of 0.25% of RFPE could form nanoemulsion particle aggregate with good dispersion. The varied concentrations of RFPE statistically indicated no significant differences among adhesive, spread property, and viscosity of all formulas. Formula 1 showed the highest sunscreen protecting factor with the value of sun-protecting factor at 6.450±0.002, followed by F4, F3, and F2 with the values in sequence at 9.370±0.002, 10.120±0.001, and 13.120±0.001, respectively. The antiradical activity of the gel nanoemulsion RFPE with inhibitory concentration 50% (IC50) value was at 9.32±0.05 μg/ mL. Meanwhile, the higher value of branded product and Vitamin E, which IC50 were 40.41±0.97 and 10.41±0.05 μg/mL, respectively. In contrast, gel nanoemulsion of RFPE had the lowest inhibition on FTC method. The highest inhibition potency was showed by Vitamin E (79.07±7.62%), followed by branded product (60.07±13.23%) as comparison.Conclusions: The gel nanoemulsion of RFPEs of FIII had a good physical stability and sunscreen protection activity. The antioxidant activity of gel nanoemulsion of RFPE by DPPH and FTC methods were IC50 value of 9.32±0.05 μg/mL and % inhibition of 51.09±0.99%.

Effects of Rambutan Peel Extract to The Number of Erythrocytes and Haemoglobin in Rats Exposed to Cigarette Smoke

Cigarette smoke is one of the exogenous free radicals sources. When it is inhaled, its activity may damage the structure of erythrocyte membrane function. The impacts of free radicals can be reduced through the provision of antioxidants. Rambutan fruit peel contains the phenolic compound in the form of polyphenols that are antioxidants. The purpose of this study is to determine the effect of rambutan fruit peel extracts to the number of erythrocytes and haemoglobin in rats exposed to cigarette smoke. This design used Post Test Control Group Design. A sample of 25 rats was divided into five groups, each group consisting of 5 rats. The positive control group (K+) were given a standard food and drinking water. The negative control group (K) by three cigarettes, the treatment group (KP1, KP2, KP3) by three cigarettes and skin extract of rambutan each treatment group with a dose 15 mg/kg, 30 mg/kg and 45 mg/kg for 30 days. Data on the number of erythrocytes and haemoglobin in rat blood was analysed with LSD and to determine the optimum dosage was analysed by using regression test. Research results shown that the content of rambutan fruit peel extract may increase the number of erythrocytes and haemoglobin of blood. Conclusions from this research are the rambutan fruit peel extract at a dose of 45 mg/kg body weight can increase and maintain the number of erythrocytes and haemoglobin in the blood of rat exposed to cigarette smoke.

Analisis Antioksidan Ekstrak Etil Asetat Dari Kulit Buah Rambutan (Nephelium Lappaceum) dengan Menggunakan Metode dpph (1,1 difenil-2-pikrilhidrakzil)

Rapiah rambutan fruit leather (Nephelium lappaceum) is one of the traditional medicine to cure various diseases such as fever and dysentery. Scientific research previously stated rambutan fruit peel skin Rapiah rambutan (Nephelium lappaceum) potentially have antioxidant content. Through this research can know the effect of solvent ethyl acetate to extract optimal rambutan fruit skin in antioxidants withdrawal. The method used for extraction is macerated using methanol and partitioned with liquid-liquid extraction using ethyl acetate solvent with a ratio (1:3), (1:4) and (1:5) which produces a thick rind extract rambutan. The extract was tested color and separated by thin layer chromatography (TLC) using the eluent butanol: glacial acetic acid: water (BAA) (4: 1: 5). Antioxidants are determined by testing against DPPH free radicals by measuring the absorbance of DPPH (1,1-diphenyl-2-pikrilhidraksil) at a wavelength of 517 nm. So that the results of this study showed the highest % reduction obtained at a ratio (1:3).