Development of high fiber rich antioxidant biscuits from purple and orange sweet potato peels

Sweet potato peel (SPP), which consist of various natural bioactive compounds, could play an important role in ameliorating chronic diseases such as cancer, cardiovascular diseases, and other degenerative diseases and yet remained underutilized. The current study investigated the effect of orange or purple SPP powder at different level of substitution (2, 5, 10%) in the production of biscuits on the proximate, antioxidant potentials and consumer acceptance. Dietary fibre increased significantly (P < 0.05) with an increase in SPP powder, ranging from 2 to 2.3 g/100 g. The total phenolic content of the biscuits was between 101.21 and 147.7 GAE/mL, total flavonoid ranged from 22.7 to 42.2 RU/mL, ABTS radical content ranged from 2.7 to 42.2 (µg ascorbic/mL). Acceptable biscuits were obtained by incorporating 2% SPP powder. Thus, SPP powder could be used as a functional and nutraceutical ingredient in biscuit production.

Utilization Pemanfaatan Ekstrak Kulit Ubi Jalar Ungu Sebagai Pengganti Crystal Violet pada Pewarnaan Gram

Purple sweet potato has the high anthocyanin content. The anthocyanin content in purple sweet potato skin is higher than the anthocyanin in the tubers, namely 52.84-729.74 mg/100g while the tubers are 110.51 mg/100g. Natural dyes that have the potential to be extracted include anthocyanins. This research aimed to test anthocyanin dyes in purple sweet potato peel extract as the substitute for crystal violet in gram staining. The type of research used Quasi Experiments. This research was conducted in the Microbiology Laboratory of the Hasanuddin University Medical Faculty. In this research, extraction was carried out by using the solvent of Ethanol : Acetic Acid : Water (25: 1: 5). Furthermore, gram staining was carried out by using purple sweet potato peel extract using a concentration of 60%, 70%, 80%, 90%, 100% and crystal violet as positive control. The results of this research indicate that the staining used purple sweet potato peel extract concentrations of 60%, 70%, 80%, 90% in gram-positive Staphylococcus bacteria isolates showed poor bacterial staining results because the bacteria were not purple when compared to crystal violet dye. Where as at the concentration of 100% it showed good bacterial staining results because the bacteria was purple. Meanwhile, gram-negative e.coli bacteria isolates at the concentration of 60%, 70%, 80%, 90%, 100% showed good bacterial staining results because the bacteria were red. Suggestions for further research to do maceration longer.

Preparation and Characterization of Super-Absorbing Gel Formulated from κ-Carrageenan–Potato Peel Starch Blended Polymers

κ-carrageenan is useful for its superior gelling, hydrogel, and thickening properties. The purpose of the study was to maximize the hydrogel properties and water-absorbing capacity of κ-carrageenan by blending it with starch from potato peels to be used as safe and biodegradable water-absorbent children’s toys. The prepared materials were analyzed using FTIR and Raman spectroscopy to analyze the functional groups. Results showed that there was a shift in the characteristic peaks of starch and κ-carrageenan, which indicated their proper reaction during blend formation. In addition, samples show a peak at 1220 cm−1 corresponding to the ester sulfate groups, and at 1670 cm−1 due to the carbonyl group contained in D-galactose. SEM micrographs showed the presence of rough surface topology after blending the two polymers, with the appearance of small pores. In addition, the presence of surface cracks indicates the biodegradability of the prepared membranes that would result after enzymatic treatment. These results are supported by surface roughness results that show the surface of the κ-carrageenan/starch membranes became rougher after enzymatic treatment. The hydrophilicity of the prepared membranes was evaluated from contact angle (CA) measurements and the swelling ratio. The swelling ratio of the prepared membranes increased gradually as the starch ratio increased, reaching 150%, while the water-uptake capacity increased from 48 ± 4% for plain κ-carrageenan to 150 ± 5% for 1:2 κ-carrageenan/starch blends. The amylase enzyme showed an effective ability to degrade both the plain κ-carrageenan and κ-carrageenan/starch membranes, and release glucose units for up to 236 and 563, respectively. According to these results, these blends could be effectively used in making safe and biodegradable molded toys with superior water-absorbing capabilities.

Potato Peel Based Carbon–Sulfur Composite as Cathode Materials for Lithium Sulfur Battery

Lithium sulfur battery has become one of the promising rechargeable battery systems to replace the conventional lithium ion battery. Commonly, it uses carbon–sulfur composites as cathode materials. Biomass based carbons has an important role in enhancing its electrochemical characteristics due to the high conductivity and porous structures. Here, potato peel wastes have been utilized to prepare porous carbon lithium sulfur battery through hydrothermal carbonization followed by the chemical activation method using KOH. After sulfur loading, as prepared carbon–sulfur composite shows stable coulombic efficiencies of above 98% and a reversible specific capacity of 804 mAh g−1 after 100 cycles at current density of 100 mA g−1. These excellent electrochemical properties can be attributed to the unique structure of PPWC showing mesoporous structure with large specific surface areas. These results show the potential application of potato peel waste based porous carbon as electrode’s materials for lithium sulfur battery.

KARAKTERISTIK TEPUNG KULIT KENTANG (Solanum tuberosum) SEBAGAI BAHAN PANGAN SUMBER KALIUM

Potato peel flour (Solanum tuberosum) is a flour that has a potential to be developed as a food source of potassium. This research was conducted to determine the chemical properties of potato peel flour. Potato peel flour is carried out in several stages: peeling potatoes; soaking in 0.3% sodium bisulfite (NaHSO3) solution for 60, 90 and 120 minutes; drying; milling; and sifting. Parameters observed were water content, ash content, protein, fat, carbohydrates and potassium (K). Potato peel flour with various immersions produced has the characteristics of water content (7.84 – 9.03%), ash content (4.15 – 4.67%), protein (11.35 – 11.60 %), fat ( 0.74 – 0.87%), carbohydrates (74.63 – 75.26%), and potassium (1231.32 – 1671.86 mg/100 g). Based on the potassium content, potato skin flour with the highest potassium content was soaked for 120 minutes.

Valorization of potato peel residues to produce a bioflocculant to be used in the treatment of liquid effluents

The present study aims primarily to investigate the flocculation capacity of a novel potato peel-based bioflocculant in wastewater treatment. The analysis of wastewater revealed high COD and BOD5 contents that could respectively reach the values 529.08 mg O2/l and 317.03 mg O2/l. In addition, the effect of experimental parameters such as the pH, coagulant/flocculant dosage, and contact time, was studied using the coagulation-flocculation treatment technique. The experiments were carried out with a lab-scale jar-test apparatus where aluminum chloride (AlCl3) was used as a coagulant agent. It should be noted that the optimal dose of AlCl3 was equal to 0.6 g at 10 mn, with turbidity reduction of 99.01%. Moreover, the flocculation tests showed higher turbidity removal (98%), for a flocculant dosage of 0.2g. The results obtained in this study indicated that using the natural potato peel-based flocculant, in the presence of a coagulant, provides an effective and environmentally friendly coagulation option for wastewater treatment.

Identification and Recovery of Valuable Bioactive Compounds from Potato Peels: A Comprehensive Review

Nowadays, the potato is one of the most cultivated and consumed food crops in the world and, in recent years, its production has experienced a sharp increase. Its industrial processing generates several by-products that are wasted and cause economic and environmental problems. Among them, potato peel stands out, representing up to 10% of the total potato residues obtained in the processing. On the other hand, these wastes, in addition to presenting antioxidant compounds, are rich in interesting chemical compounds of great value in a biorefinery model. This review summarizes the main compounds present in potato skins as well as the most used and innovative extraction methods employed for their isolation, with special emphasis on the fractions with biological activities. In addition, a sustainable biorefinery proposal focused on obtaining high added-value products with potential applications in the pharmaceutical, food, nutraceutical, or cosmetic industries is included.