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This study examines the co‐digestion of landfill leachate (LFL) with pineapple peel, focusing on biogas production. The study was conducted with a lab‐scale batch anaerobic digester using a 30 L working volume batch completely mixed reactor at 35 °C to investigate the monodigestion of leachate and of pineapple peel and their co‐digestion with three different mixing ratios. The results of all of the experiments in the study were fitted with first‐order kinetic models to compare the behavior of different batches through rate constants (k). As expected, the anaerobic digestion of 25 L leachate achieved a biogas yield of 38 L kg−1 volatile solids (VS)consumed and a VS removal efficiency of 30%, both markedly lower than those achieved with 3 kg VS pineapple peel per m3 in 25 L tap water (513 L kg−1 VSconsumed biogas yield and 80% VS removal efficiency). The leachate, which had a fixed volume of 25 L, was mixed with 1, 2, and 3 kg VS pineapple peel m−3. The results showed that co‐digestion with 2 kg VS pineapple peel m−3 achieved the highest biogas yield of 431 L kg−1 VSconsumed and approximately 80% VS and 90% chemical oxygen demand (COD) removal efficiency with stable conditions in the reactor. The first‐order kinetics equation was selected to characterize the anaerobic digestion and was able to describe and compare the anaerobic digestion processes of the experiments. The rate constants (k) were 0.25, 0.22, and 0.18 day−1 for co‐digestion with 1, 2, and 3 kg VS pineapple peel m−3. [ABSTRACT FROM AUTHOR]

The piggery industry in Nigeria is on the verge of collapsing due to the high cost of conventional feed resources including wheat offal and palm kernel cake that usually form bulk in the diets of pigs. This study was, therefore, designed to compare the chemical composition of orange pulp meal, pineapple peel meal, and wheat offal and evaluate their feeding value in pig rations. The orange pulp and pineapple peels were dried on a concrete floor and analyzed for chemical composition. Three experimental diets were formulated with orange pulp and pineapple peel meals replacing wheat offal as a fibre source. Thirty crossbred (Chester white x Landrace) growing pigs with an average initial weight of 8.20 -- 8.75kg were distributed into three groups, with ten animals per group, and assigned to the three experimental diets. The average daily feed intake and weight gain were monitored throughout the 56-day duration of the experiment. Seven days to the end of the experiment, three pigs randomly selected for the digestibility trial were individually housed in metabolism crates and allowed 5 days of adaptation to the crates and feed before faecal collection commenced. Animals were fed the experimental diets at approximately 4% of their body weight, and the faeces of the animals were collected for 5 days. The determination of the nutrient composition of feed and faecal samples was performed. Data collected were subjected to analysis of variance using a completely randomized design. The result indicated that samples were significantly (P<0.05) different in crude protein composition, with the wheat offal having the highest value corresponding to 9.21 ± 0.12%. Orange pulp had the highest content of ash (6.72 ± 0.12%). The gross energy values were 15.23MJ/kg, 15.31MJ/kg and 16.15MJ/kg for pineapple peel, orange pulp and wheat offal, respectively. The highest manganese concentration was observed in wheat offal (5.19± 0.11mg/l), while orange pulp and wheat offal were higher in sodium and phosphorus concentrations. The pigs fed an orange pulp meal diet recorded the highest average daily weight gain (0.31 kg) and a superior feed conversion ratio (4.19) relative to others. Digestibility values were similar across the three treatment groups. It was, therefore, concluded that orange pulp and pineapple peal meal could serve as alternative fibre sources in growing pigs' rations. [ABSTRACT FROM AUTHOR]

Agro-residues, including banana peel, pineapple peel, mango peel, apple peel, and coconut husk, were utilized to produce extracellular polysaccharide (EPS) via solid state fermentation(SSF) by the fungus, Trichoderma hamatum. EPS production was highest in pineapple peel (84.2 ± 0.4 mg/g), followed by mango peel (70.3 ± 0.41 mg/g) (p<0.01). The SSF bioprocess was optimized via a two-level full factorial design and response surface methodology. The effects of five selected variables on EPS biosynthesis, namely, the concentrations of glucose (10 to 30%), ammonium sulphate (0.1 to 1%), yeast extract (0.5 to 2%), MgSO4 (0.01 to 0.1%), and medium pH (4.5 to 6.5), were analyzed via a full factorial design (FFD). The EPS production ranged widely from 15.3 to 576.2 mg/g substrate. Three significant variables affecting EPS production were assessed in central composite design (CCD) to optimize concentrations of MgSO4, and glucose, and the pH. The designed CCD model was fitted to the quadratic model and was significant (p<0.0001). For 50 μL of EPS, the scavenging ratio was 43.4 ± 4.1% at a concentration of 200 μL (78.5 ± 6.9 μL) (p<0.01). The extracted EPS exhibited an alpha-glucosidase inhibitory effect (p<0.001). Solid-state fermentation allows the utilization of low-cost biomass for EPS production and the application of T. hamatum EPS as a natural antioxidant and α-glucosidase inhibitor. [ABSTRACT FROM AUTHOR]

Agro-residues, including banana peel, pineapple peel, mango peel, apple peel, and coconut husk, were utilized to produce extracellular polysaccharide (EPS) via solid state fermentation(SSF) by the fungus, Trichoderma hamatum. EPS production was highest in pineapple peel (84.2 ± 0.4 mg/g), followed by mango peel (70.3 ± 0.41 mg/g) (p

Demand for vegetables is very high due to Indonesia's relatively rapid population growth and increasing public knowledge about the benefits of adopting good eating habits to increase the nutritional content of food. Water spinach (Ipomoea reptans Poir.) is a type of vegetable that is much sought after by Indonesian people. These plants require food in the form of water and nutrients to support their growth and productivity. Eco enzyme is an organic fertilizer that contains quite a lot of nutrients needed by plants, so it can increase plant growth. Eco enzyme is the result of fermentation of organic kitchen waste from fruit peels, vegetables, granulated sugar (brown sugar, brown sugar, or cane sugar), and water. The aim of this research is to find out how well the development of kale plants is influenced by eco enzyme processing from household waste. A completely randomized design (CRD) with one factor, namely the frequency of administering eco enzyme to water spinach seeds using three replications for each treatment, was used to construct this research. The treatments used were (E0): control, (E1): application once a week, and (E2): application once every 2 weeks. Treatment (E0) was not given eco enzyme but was watered using tap water, while treatments (E1 and E2) were watered using 50 mL of eco enzyme each/pot. The research results show that the production of eco enzyme from household waste can be applied to support the growth and productivity of kale plants. From application to kale plants, each treatment did not show a significant difference in results. [ABSTRACT FROM AUTHOR]

Pineapple peel waste has high bioactivity in the form of polyphenols and flavonoids; therefore, in the current research, valorization of agro-processing waste of pineapple peel was carried out to extract BAC using the Microwave-assisted extraction (MAE) method as a green technology.Herniarin, the targeted BAC from pineapple peel extract, was identified and isolated using HRLC-MS/MS and measured using HPLC. Lipophilic liposomes made by ethanol injection technique using Phosal 50 PG encapsulated heriarin (7-Methoxy coumarin); the formulations were analysed for size distribution, entrapment efficiency, and surface morphology. To stabilise the produced formulation, liposomes were freeze dried with mannitol as a cryoprotectant. During a six-month stability investigation, the entrapment efficiency of lyophilized liposome ranged from 99.74 ± 0.24 to 91.56 ± 0.34. Cookies were prepared in concentrations of 0.5%, 1.0%, and 1.5% herniarin (with and without encapsulation) to determine the effect of antioxidant activity, physicochemical, and microbial properties after 3 months of storage. Cookies with encapsulated BAC (MCNWE) had free fatty acid values ranging from 0.21 ± 0.08 to 1.00 ± 0.04, and antioxidant capacity ranging from 18.02 ± 0.04 to 13.98 ± 0.05.It can be inferred that cookies with encapsulated BAC have the highest antioxidant capacity and can be used as functional food with fair overall acceptability in market. [ABSTRACT FROM AUTHOR]

The experiment aimed to study the nutritional components of three unconventional feedstuffs (brewer's grains, Siraitia grosvenorii pulp, and pineapple peel) and their degradation characteristics in the buffalo's rumen. The experiment selected three healthy Murrah crossbred female buffaloes with permanent rumen fistulas and conducted in vivo tests using the nylon bag method. The results showed that the degradation rates of DM, CP, NDF, and ADF of the three unconventional feedstuffs gradually increased in the buffalo's rumen over time. The DM, NDF, and ADF ruminal degradation rates of pineapple peel were significantly higher than those of brewer's grains and Siraitia grosvenorii Pulp at various time points (P<0.05). Except for 12 h and 72 h, the CP degradation rate of pineapple peel at various time points was significantly higher than that of brewer's grains and Siraitia grosvenorii pulp (P<0.05), and the rapid degradation part of DM and CP of pineapple peel was significantly higher than brewer's grains and Siraitia grosvenorii pulp (P<0.05). The effective degradation rates of DM, NDF and ADF of the three roughages were ranked as pineapple peel > brewer's grains > Siraitia grosvenorii pulp. The study suggests that pineapple peel and brewer's grains have higher nutritional value and can serve as high-quality roughage for buffaloes. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pineapple peel contributing about 29–40% of total pineapple waste was valorised to biopolymer-based antimicrobial films. Chitosan films were formulated with 1–3% of pineapple peel extract (PPE) and glycerol (30%) as a plasticizer. The moisture content of the films reduced from 28.33 ± 0.66 to 19 ± 0.49% while water solubility reduced from 16.90 ± 0.93 to 13.12 ± 0.59% with increasing PPE concentration. The addition of PPEs decreased the tensile strength and elongation at break of the films indicating disruption of the crystalline structure of chitosan and weakening of the intramolecular H-bonding, thereby providing flexible nature to these films. Chitosan-PPE films displayed more homogenous and well-ordered surface morphology compared to pure chitosan films. The antioxidant activity of the chitosan-PPE films was evaluated by DPPH, ABTS and CUPRAC assays. Chitosan films with 3% PPE exhibited the highest antioxidant activity. DPPH assay determined 8.70 ± 0.18 μmol TE/g DW while ABTS and CUPRAC assay determined 18.97 ± 0.57 μmol TE/g DW and 51.65 ± 0.87 μmol TE/g DW respectively. The chitosan-PPE films also exhibited inhibitory zones against foodborne bacterial organisms. The maximum area of inhibition was observed against B. cereus (21.36 ± 0.30 mm) and S. aureus (22.36 ± 1.32 mm) when 3% PPE was incorporated into the chitosan matrix. On the other hand, for the gram-negative bacterial strains, E. coli and S. typhimurium, comparatively lower inhibition zones were observed at 17.46 ± 0.83 mm and 12.9 ± 0.1 mm, respectively. [ABSTRACT FROM AUTHOR]

Pineapple peel is a kind of agricultural and forestry waste and biochar is an environmentally friendly adsorbent, but the adsorption capacity of biochar needs to be improved, and it is not easy to separate after adsorption. In order to solve these problems, Zn-Al layered double oxide/magnetic pineapple peel biochar (ZnAl-LDO/MPC1) was prepared based on Zn-Al layered double hydroxide/magnetic pineapple peel biochar (ZnAl-LDH/MPC1) calcined at 400 °C with 10 °C/min for 4 h. According to SEM, XRD, FTIR, BET analysis, and magnetic analysis, characterization of the samples was carried out. Under different pH, contact time, original concentration of methylene blue (MB), and ionic strength, the adsorption experiments of removing MB on ZnAl-LDO/MPC1 were conducted. The adsorption kinetics of ZnAl-LDO/MPC1 for MB conforms to the quasi-second-order kinetic model, and the adsorption isotherm of ZnAl-LDO/MPC1 for MB fits the Langmuir isothermal adsorption model. ZnAl-LDO/MPC1 can be applied four times in the circulatory system. The findings suggested that ZnAl-LDO/MPC1 has application prospects as an efficient and recyclable MB adsorbent for the treatment of dye wastewater. [ABSTRACT FROM AUTHOR]

This study investigates the viability of utilizing microcellulose extracted from pineapple peel waste as a sustainable and cost-effective matrix material for polypyrrole (PPy)-based capacitors. A novel PPy/microcellulose composite was synthesized with varying pyrrole volumes (1-2 mL) and characterized using Fourier Transform Infrared (FTIR) and Xray diffraction (XRD) analyses. FTIR analysis confirmed successful cellulose isolation, while XRD indicated a similarity between the extracted pineapple peel and commercial cellulose. Capacitor cells were fabricated using the synthesized composites, and their capacitance performance was evaluated. Notably, cells containing 2 mL of PPy exhibited the highest capacitance values. Additionally, the source of cellulose had minimal influence on the resulting capacitance. This study suggests that microcellulose derived from pineapple peel waste holds promise as a sustainable alternative to traditional matrix materials for high-performance capacitors. [ABSTRACT FROM AUTHOR]

As a common antibiotic, tetracycline (TC) is extensively used in the prevention and treatment bacterial dis¬eases in animals and is also used as a feed additive to promote the growth of animals. In this paper, a fluorescence quenching method based on nitrogen doped carbon quantum dots (N-CQDs) derived from pineapple peel was established for the rapid detection of TC. The blue fluorescent N-CQDs with high quantum yield were prepared by the hydrothermal method using pineapple peel and diethylenetriamine as precursors. The structure of N-CQDs was characterized by trans¬mission electron microscope, fourier infrared spectroscopy and X-ray photoelectron spectroscopy. The results showed that the average particle size of N-CQDs was about 3.53 nm, which was mainly composed of C, N and 0, and the surface has oxygen-containing and nitrogen-containing groups. The fluorescence of N-CQDs was effectively quenched by static quenching and internal filtering effect. Under the optimal experimental conditions, the method had good linearity within 0.3-40 g/mL, and the detection limit was calculated to be 89.26 g/L. Moreover, the detection method has been applied to the determination of TC in pork, the recovery rate was 98.40%-106.02%. The results showed that the detection method could be applied to the rapid determination of TC in pork. [ABSTRACT FROM AUTHOR]

Porous carbon materials have been widely used to remove pollutants from the liquid-phase streams. However, their limited pore properties could be a major problem. In this work, the effects of post-washing methods (i.e., water washing and acid washing) on the textural characteristics of the resulting biochar and activated carbon products from pineapple peel biomass were investigated in the carbonization and CO2 activation processes. The experiments were set at an elevated temperature (i.e., 800 °C) holding for 30 min. It was found that the enhancement in pore property reached about a 50% increase rate, increasing from 569.56 m2/g for the crude activated carbon to the maximal BET surface area of 843.09 m2/g for the resulting activated carbon by water washing. The resulting activated carbon materials featured the microporous structures but also were characteristic of the mesoporous solids. By contrast, the enhancement in the increase rate by about 150% was found in the resulting biochar products. However, there seemed to be no significant variations in pore property with post-washing methods. Using the energy dispersive X-ray spectroscopy (EDS) and the Fourier Transform infrared spectroscopy (FTIR) analyses, it showed some oxygen-containing functional groups or complexes, potentially posing the hydrophilic characters on the surface of the resulting carbon materials. [ABSTRACT FROM AUTHOR]

It has been reported that pineapple (Ananas comosus) contains healthy nutrients and phytochemicals associated with antioxidant and anti-inflammatory capacities. However, a substantial amount of pineapple residue is produced due to a lack of valorization applications at the industrial scale, resulting in the loss of valuable nutrients. Solid-state fermentation (SSF) is proposed as an innovative strategy to enhance the release of bound phenolics from pineapple residues. In this work, the effects of SSF of pineapple peels with Lactobacillus plantarum, Lactobacillus rhamnosus, and Aspergillus oryzae on the release of phenolic compounds and their antioxidant and anti-inflammatory activities were evaluated, respectively. Pineapple peel extracts after SSF showed an increase in the release of phenolic compounds (248.11% with L. plantarum, 182% with A. oryzae, and 180.10% with L. rhamnosus), which led to an increase in the cellular antioxidant (81.94% with L. rhamnosus) and anti-inflammatory potential (nitric oxide inhibition of 62% with L. rhamnosus) compared to non-fermented extracts. Therefore, SSF of pineapple peels with L. plantarum, L. rhamnosus, and A. oryzae thrives as a new approach for the production of secondary metabolites with remarkable biological benefits, which can be the precursors for novel biofortified and nutraceutical-enriched foods that meet the needs of the most demanding and health-conscious consumers. [ABSTRACT FROM AUTHOR]

Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Food and agricultural wastes have led to environmental and landfill issues. Nonetheless, biowastes can be converted into valuable bioproducts, such as pectin. Hence, this study investigated microwave-assisted extraction (MAE) optimisation to extract pectin from pineapple (Ananas comosus) peel. Microwave power (400–600 W), pH (1.5–2.5), and solid-to-liquid (S/L) ratio (1:10–1:30 w/v) were applied to optimise pineapple peel pectin (PPP) extraction, as well as to determine the interaction effects on pectin yield and anhydrouronic acid (AUA) content using Box–Behnken Design (BBD). The highest yields of pectin (2.43 ± 0.03%) and AUA content (54.61 ± 0.21%) were achieved at optimised conditions (600 W, pH 1.52, and 1:10 g/mL of S/L ratio), which were 35.75% and 7.93% higher than their values prior to optimisation, respectively. The PPP displayed Newtonian behavior at low concentrations (0.1, 0.5, and 1.0% w/v), but showed pseudoplastic flow behavior at a higher concentration (2.0% w/v). The PPP viscosity was temperature-dependent, as its apparent viscosity gradually decreased with temperature increment from 25 to 75 °C with increasing shear rate. The PPP emulsion stability improved by 1.06- and 1.12-fold after 30 days of storage at 4 and 25 °C, respectively, in comparison to commercial pectin. The MAE method enhanced the pectin yield by 21.5% than the conventional heating technique. The MAE qualifies as an alternative for pectin extraction from pineapple peel, as it demands less solvent and shorter extraction time. [ABSTRACT FROM AUTHOR]

Phenolic compounds that are present in pineapple by-products offer many health benefits to the consumer; however, they are unstable to many environmental factors. For this reason, encapsulation is ideal for preserving their beneficial effects. In this work, extracts were obtained by the combined method of solid-state fermentation with Rhizopus oryzae and ultrasound. After this process, the encapsulation process was performed by ionotropic gelation using corn starch, sodium alginate, and Weissella confusa exopolysaccharide as wall material. The encapsulates produced presented a moisture content between 7.10 and 10.45% (w.b), a solubility of 53.06 ± 0.54%, and a wettability of 31.46 ± 2.02 s. The total phenolic content (TPC), antioxidant capacity of DPPH, and ABTS of the encapsulates were also determined, finding 232.55 ± 2.07 mg GAE/g d.m for TPC, 45.64 ± 0.9 µm Trolox/mg GAE for DPPH, and 51.69 ± 1.08 µm Trolox/mg GAE for ABTS. Additionally, ultrahigh performance liquid chromatography (UHPLC) analysis allowed us to identify and quantify six bioactive compounds: rosmarinic acid, caffeic acid, p-coumaric acid, ferulic acid, gallic acid, and quercetin. According to the above, using ionotropic gelation, it was possible to obtain microencapsulates containing bioactive compounds from pineapple peel extracts, which may have applications in the development of functional foods. [ABSTRACT FROM AUTHOR]

The waste and inadequate management of organic waste generates environmental problems in cities; this research proposes the reuse of waste such as pineapple peel to create new eco-friendly materials. In order to determine whether it is feasible or not, it is necessary to perform the physicochemical characterization of the peel, describing in detail the performance of the process, measuring turbidity, color, acidity by titration, boiling point, humidity, total suspended solids, Brix grades, mesh screening, analysis of the degrading fungus from the peel to the weather and PH. The main conclusion is that pineapple peel juice contains favorable properties for making new eco-friendly materials. [ABSTRACT FROM AUTHOR]

Endophytic bacteria are known to contain various bioactive substances. Pineapple peel (Ananas comosus L.) is a waste product utilized in environmental preservation. The present study is focused on the isolation of endophytic bacteria from pineapple peel, and the assessment of their antibacterial activity. The ethyl acetate extracts of isolated bacteria were tested for their antibacterial activity using the disc diffusion method. The components of the bacterial extract were identified by UPLC-MS/MS analysis. Extract of the endophytic bacteria (Bacillus velezensis WSM-1) had the highest activity with an inhibition zone diameter of 17.71 mm and 15.87 mm against Staphylococcus aureus and Escherichia coli, respectively. UPLC MS/MS analysis identified several compounds, including; 6-Methoxyquinoline, 2-(6-amino-9H-purin-9-yl)-5-(hydroxymethyl)oxolane-3,4-diol, Aklavin, Maltotriose, Cholestanetriol, Piperic acid, Isoflavone, Paromomycin, and Mycaloide B. Paromomycin is known to have antibacterial activity. It is a type of antibiotic that belongs to the aminoglycoside class and is commonly used to treat infections caused by gram-negative bacteria. The results of the present study suggest that the endophytic bacterial isolate from pineapple peel have potential antibacterial activity and there is a need for further study to isolate and characterize the antibacterial active constituents. [ABSTRACT FROM AUTHOR]

As the demand for energy continues to rise, it is still primarily met by fossil fuels and non-renewable energy sources. In addition, oil production, particularly in older fields, is declining. The enhanced oil recovery (EOR) method utilized in this study is surfactant injection with the addition of waste pineapple peel. The experiment was carried out in a controlled laboratory setting, using surfactant and brine solutions with salinities of 5,000 ppm and 12,000 ppm, respectively. The concentration range of alpha olefin sulfonate (AOS) surfactant employed ranged from 0.2% to 0.6% (2×10-6 m3 and to 0.6% from 1×10-3 m3). The solution was tested at two different temperatures, specifically 30°C and 60°C. The solution was tested with the addition of the pineapple peel and without pineapple peel. The density, viscosity, and interfacial tension of the two solutions were determined using laboratory measurements. The subsequent procedure involves the injection of the core sample in order to determine the oil recovery factor. The interfacial tension (IFT) values obtained were 17.5 mN/m in the absence of additives and 15.4 mN/m in the presence of additives derived from pineapple peel. The recovery factor for a solution with a salinity of 12,000 ppm and a concentration of 0.6% is determined to be 42.01%. Additionally, the recovery factor for a surfactant solution with the addition of pineapple peel is found to be 44.26%. Based on the findings of this study, the utilization of waste pineapple peel demonstrates a beneficial impact on the process of oil production.

Kepok banana and pineapple are horticultural commodities found in West Kalimantan. The two fruits are generally used as processed foods such as fried bananas and pineapple jam. The use of fruit as food often leaves the peel as a by-product, which can produce waste twice the weight of the food consumed. Meanwhile, waste utilization is an innovation in food processing into functional products which are developed into hard candy. Therefore, this research aims to the specific and non-specific characterization of raw materials for making candy, namely the combination of banana and pineapple peel extract (KP-KN). The characterization is organoleptic tests on the content of ethanol-soluble and water-soluble extracts. The Total phenolic content was determined by the Follin ciocalticeu method with UV/Vis spectrophotometry. Furthermore, antioxidant activity tests with DPPH and FRAP methods using UV/Vis spectrophotometry and ELISA to determine antioxidant activity. The mineral content was observed using the molybdate vandalate method with UV/vis spectrophotometry and ICP-MS, Heavy metal contamination using the ICP-MS tool, and microbial contamination using the plate method. Moreover, the infundation process was carried out on banana and pineapple peels, and the results were evaporated using a food dehydrator to obtain a combination extract. The results showed that the organoleptically KP-KN combination extract had a bitter taste, pineapple smells, 15.57% ash content, ethanol soluble extract content of 55.10%, and 47.99% water-soluble extract. Also, the total phenolic of 6.22 g/Kg, as well as the mineral content of Potassium (K), Calcium (Ca), Iron (Fe), Magnesium (Mg), Zinc (Zn), and Phosphorus (P), which were 47.23 g/Kg, 291.43 mg/Kg,

Biosurfactants have wide applications in several industries. However, high production costs and safety concerns have limited their comprehensive use. Twenty-five strains of lactic acid bacteria, isolated from fermenting maize slurry, were screened for biosurfactant production using the emulsification activity (E24) assay. The selected bacterium was identified molecularly using the 16S rRNA gene sequencing as Lactobacillus plantarum OG8. The effect of some cultural factors on biosurfactant production from the bacterium, using pineapple peel as a low-cost substrate, was investigated. The optimum yield of biosurfactant occurred at a 48 h incubation period, using glucose and peptone as carbon and nitrogen sources, respectively. The biosurfactant was characterized to possess mostly carbohydrates, followed by protein and lipid contents. Optima pH 10.0 and temperature 60 °C were the best for the biosurfactant activity. The biosurfactant exhibited antimicrobial activity against bacterial pathogens Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae, at a concentration of 5.0 mg/mL. The use of pineapple peel as a low-cost substrate for biosurfactant production from Lactobacillus plantarum OG8 will serve for cost-effective production. The biosurfactantt produced exhibited promising properties such as thermostability and antimicrobial activity against food spoilage and pathogenes that could make it suitable for food processing and preservation.

This study was designed to assess the effects of breed and inclusion levels of sun-dried pineapple peel on the growth performance of growing rabbit bucks. Thirty-two (32) purebred growing rabbits (Chinchilla, Dutch and New Zealand White) aged between 6-7 weeks with an initial average weight of 762.25±52.66 g were used for the study. The experiment was laid out in a 3 x 4 factorial arrangement (three breeds and four dietary treatments) in a completely randomized design. The rabbits were randomly assigned to the four dietary treatments (0%, 5%, 10%, and 15% PP) with eight rabbits per treatment. The rabbits were fed for a period of 56 days. Each rabbit was housed in a separate pen. Data collected and calculated were initial weight (g), final weight (g), total weight gain (g), daily weight gain (g), total feed intake (g), daily feed intake (g), feed conversion ratio, and mortality. The data collected were analyzed using Statistix and the means with significant differences were compared using Duncan Multiple Range Test. There was no significant (p>0.05) difference in all the growth parameters for breed and graded levels except on mortality. Inclusion of up to 15% PP across all breeds gave zero mortality. This study therefore concluded that, the sun-dried pineapple peel is a suitable feedstuff for rabbit of different breeds and up to 15% PP can be used without any adverse effect on growth performance of rabbit bucks. [ABSTRACT FROM AUTHOR]

The use of non-conventional carbon sources for biosurfactant-producing microorganisms is a promising alternative in fermentation to substitute costly substrates. So, the current research used pineapple peel as a cost-effective and renewable substrate because of its rich composition in minerals and sugars and high availability. Following a 22 full factorial design, a bacterial strain of Bacillus subtilis produced biosurfactants in fermentative media containing different concentrations of glucose and concentrated pineapple peel juice (CPPJ). The influence of these two independent variables was evaluated according to three different responses: surface tension reduction rate (STRR), emulsification index (EI24), and concentration of semi-purified biosurfactant (SPB). The maximum value for STRR (57.63%) was obtained in media containing 0.58% glucose (w/v) and 5.82% CPPJ (v/v), while the highest EI24 response (58.60%) was observed at 2% glucose (w/v) and 20% CPPJ (v/v) and maximum SPB (1.28 g/L) at 3.42% glucose (w/v) and 34.18% CPPJ (v/v). Statistical analysis indicated that the CPPJ variable mostly influenced the STRR and SPB responses, whereas the EI24 was significantly influenced by pineapple peel juice and glucose contents. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Chinese Society of Animal Science is the property of Chinese Society of Animal Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Furfurylamine is a versatile compound used in perfumes, polymers, pharmaceuticals, and agrochemicals. To address the costly and inefficient furfural bioamination process, a strategy combining ω-transaminase with other enzymes was applied to construct a multi-enzyme system. Pyruvate decarboxylase (PDC) might transform amination byproducts into acetaldehyde, promoting the forward bioreaction. E. coli 20PDC was created by co-expressing PDC and mutated ω-transaminase (HN), which could be applied to efficiently aminate furfural, vanillin and 5-hydroxymethylfurfural into furfuryalmine, vanillylamine, and 5-hydroxymethyl-2-furfurylamine, respectively. Pineapple peel can be used as a suitable feedstock for production of furfural and furfurylamine. A chemobiological cascade reaction was built to transform pineapple peel into furan-based amines in deep eutectic solvent ChCl: p A-H 2 O. In ChCl: p A (10 wt%) at 170 °C, pineapple peel was converted to furfural within 10 min (65.2% yield, based on xylan), and the pineapple peel-derived furfural was resoundingly converted to furfurylamine at 35 °C with D -alanine (D -alanine:substrate = 2:1) in ChCl: p A (20 wt%, pH 7.5). This dual-enzyme co-expression strategy reduced the amine donor loading and realized the effectual bioamination from biomass-derived aldehydes. To sum up, the strategy for synthesis of FAM from pineapple peel by tandem chemocatalysis and biocatalysis in ChCl: p A-H 2 O holds significant promising in the valorization of biomass into valuable furans. [Display omitted] • Furfurylamine (FAM) was prepared from pineapple peel via chemobiocatalytic approach. • ChCl: p A–H 2 O catalyzed pineapple peel to FUR (65.2% yield) at 170 °C for 10 min. • E. coli 20PDC was created by co-expressing PDC and mutated ω-transaminase (HN). • A small amount of D -alanine was required for the bioamination of FUR into FAM. • The FAM yield was 0.47 g FAM/(g xylan in pineapple peel). [ABSTRACT FROM AUTHOR]

It has been reported that pineapple (Ananas comosus) contains healthy nutrients and phytochemicals associated with antioxidant and anti-inflammatory capacities. However, a substantial amount of pineapple residue is produced due to a lack of valorization applications at the industrial scale, resulting in the loss of valuable nutrients. Solid-state fermentation (SSF) is proposed as an innovative strategy to enhance the release of bound phenolics from pineapple residues. In this work, the effects of SSF of pineapple peels with Lactobacillus plantarum, Lactobacillus rhamnosus, and Aspergillus oryzae on the release of phenolic compounds and their antioxidant and anti-inflammatory activities were evaluated, respectively. Pineapple peel extracts after SSF showed an increase in the release of phenolic compounds (248.11% with L. plantarum, 182% with A. oryzae, and 180.10% with L. rhamnosus), which led to an increase in the cellular antioxidant (81.94% with L. rhamnosus) and anti-inflammatory potential (nitric oxide inhibition of 62% with L. rhamnosus) compared to non-fermented extracts. Therefore, SSF of pineapple peels with L. plantarum, L. rhamnosus, and A. oryzae thrives as a new approach for the production of secondary metabolites with remarkable biological benefits, which can be the precursors for novel biofortified and nutraceutical-enriched foods that meet the needs of the most demanding and health-conscious consumers.

Pickering emulsions (PE) are systems made up of two incompatible fluids, these are stabilized by solid organic or inorganic particles located on their interface. Cellulose nanocrystals (CNCs) are sustainable and biocompatible value-added naturally occurring biomolecules which are being investigated as PE stabilizers in the cosmetic, food, and pharmaceutical industries. The objective of this research was to investigate the efficacy of pineapple cellulose nanocrystals as stabilizers for a ginger essential oil-in-water Pickering emulsion. Anionic pineapple cellulose nanocrystals were prepared by acid hydrolysis. Ginger essential oil-in-water emulsions were prepared by ultrasonication. Pineapple CNC produced stable Pickering emulsions with surface average droplet size of 4.3 μm–6.2 μm, high negative zeta potential, high viscosity, and high adsorption at the interface. Pickering emulsions by ultrasonication were stable against droplet coalescence, phase separation, and droplet flocculation for at least 8 weeks at 25 °C or 40 °C at various droplet sizes. The emulsion droplet size and volume density (droplet size distribution) were evaluated by varying the particle concentration (CNC 0.25 g/100 ml or 0.50 g/100 ml) and/or oil fraction (10–20 g/100 ml). At constant oil fraction, the emulsion viscosity increased as the nanocrystal concentration increased. The cellulose nanocrystal-stabilized ginger oil-Pickering emulsions exhibited shear-thinning characteristics of a pseudo-plastic fluid. Pineapple nanocellulose crystal -stabilized ginger oil-Pickering emulsions exhibited high stability with a creaming index of zero. CNC was found to be an effective Pickering stabilizer for oil-in-water emulsions in various food applications.

In this study, the oxidized cellulose nanofibrils from pineapple peel (PP-TOCNF) were prepared by TEMPO-mediated oxidation followed by ball milling. The influence of oxidation degree on the structure and properties of PP-TOCNF were investigated, including Fourier transform infrared spectroscopy , X-ray diffraction, atomic force microscope (AFM), X-ray photoelectron spectroscopy and thermogravimetry, as well as the potential application in aerogels. The results suggested that TEMPO oxidation facilitated the dispersion of PP-TOCNF due to the strong electrostatic repulsion between –COO− groups. Regulating oxidation degree by varying NaClO concentration could effectively adjust the –COO− content (0.167–0.550 mmol/g), zeta potential (− 18 to − 34 mV) and rheological properties. The obtained PP-TOCNF showed a long fibrillar structure, whose average diameter and CrI values gradually decreased with the increase of oxidation degree. The PP-TOCNF-based aerogels exhibited a light weight, good porosity, water absorption, and mechanical properties, which also can be easily adjusted by oxidation degree of PP-TOCNF. Furthermore, TEMPO oxidation improved the stability and shape recovery ability of aerogels in water. [ABSTRACT FROM AUTHOR]

As the food processing by-products, hericium erinaceus residues (HER) and pineapple peel (PP) are good sources of cellulose and chitosan that can be prepared into hydrogels for structuring a drug delivery system. Hydrogel is one new type biomaterial for drug delivery with excellent absorbent ability applied in wound dressing. In this research, one composite self-healing hydrogel with pH sensitivity for drug delivery system based on the Schiff-base reaction was fabricated. Therein aldehyde group of oxidized microcrystalline cellulose (OMCC) from PP were crosslinked with amino group of carboxymethyl chitosan (CMCS) from HER via Schiff-base reaction for structuring hydrogels. The structures of the prepared hydrogels were characterized. Meanwhile, its blood clotting activity and physical properties were investigated. The hydrogels show some favorable performances with suitable gel time (54 s of minimum), distinguish swelling rate (about 31.18 g/g), good mechanical, self-healing characteristic and well coagulation effect. The cumulative release of the rutin-loaded hydrogel OMCM-54 reached about 80 % within 6 h, suggesting the well-controlled release of rutin by crosslinking degree between the modified OMCC and CMCS based on Schiff-base reaction. The novel biomaterial based on hericium erinaceus residues and pineapple peel shows its potential use as wound dressing. [Display omitted] • Pineapple peel and hericium erinaceus residues were modified as hydrogel materials. • Modified cellulose/chitosan hydrogels were synthesized via Schiff base reaction. • The hydrogel shows comparable modulus with human skin and fast self-healing effect. • The prepared hydrogel exhibited good blood clotting property as wound dressing. [ABSTRACT FROM AUTHOR]

This study aims to assess the effects of the partial replacement of whole corn silage (WCS) with fermented pineapple peel residue (FPPR) on growth, serological parameters, muscle quality, rumen microorganisms, and fecal microorganisms. A total of 24 Chuanzhong black goats weighing 10.23 ± 1.42 kg were evaluated in a randomized complete trial design in accordance with the following treatments: (1) 0% FPPR in the diet, (2) 25% FPPR in the diet, and (3) 50% FPPR in the diet. In goats, the partial substitution of FPPR for WCS increased the abundance of probiotics, such as Blautia, Butyrivibrio fibrisolvens, and Ruminococcus albus, and did not exert significant effects on overall serological parameters and muscle quality. In conclusion, the partial substitution of FPPR for WCS in the diet did not impair or affect the productive performance of goats. [ABSTRACT FROM AUTHOR]

The effects of ethanolic pineapple peel extract (PPE) powder at various concentrations (0–1.50%, w/w) on the gelling properties of silver carp surimi were investigated. The pineapple peel extract produced with 0–100% ethanol, revealed that 100% ethanol had the highest bioactive properties. Surimi gels with added PPE powder demonstrated improved gel strength (504.13 ± 11.78 g.cm) and breaking force (511.64 ± 11.80 g) up to 1% PPE addition; however, as PPE concentration increased beyond 1%, the gel strength decreased. Similarly, with the addition of 1% PPE powder, more hydrophobic bonds and fewer sulfhydryl groups and free amino groups were seen. However, the gels with PPE powder added showed a slight reduction in the whiteness of the surimi gels. FTIR analysis indicated that the fortification with PPE powder brought about the secondary structure of myofibrillar proteins; peaks shifted to the β-sheet region (PPE gels) from the α-helix region (control). SEM analysis indicated that the gel with 1% PPE powder had a relatively organized, finer and denser gel architecture. Overall results suggested that the addition of PPE powder up to 1% to the surimi gels enhanced the gelling properties as well as the microstructure of the surimi. [ABSTRACT FROM AUTHOR]

The pineapple peel cellulose(PPC) was used as raw material to dissolve in an alkali/urea solution with incorporation of bentonite, then further chemically cross-linked and in-situ embedded with magnetic Fe3O4 to form composite hydrogels. The structure and dye adsorption properties of hydrogels were studied. The results confirmed the successful intercalation of bentonite and Fe3O4 in the hydrogels. The bentonite effectively improved the cross-linked porous network structure, thermal stability and swelling properties of the hydrogel. The bentonite also enhanced the methylene blue adsorption performance of the hydrogels, showing an increased saturated adsorption capacity from 28. 09 mg/g to 55. 87 mg/g. The adsorption process conformed to the pseudo-second-order kinetic model and Langmuir model, belonging to chemical adsorption and monolayer adsorption. [ABSTRACT FROM AUTHOR]

Phenolic compounds that are present in pineapple by-products offer many health benefits to the consumer; however, they are unstable to many environmental factors. For this reason, encapsulation is ideal for preserving their beneficial effects. In this work, extracts were obtained by the combined method of solid-state fermentation with Rhizopus oryzae and ultrasound. After this process, the encapsulation process was performed by ionotropic gelation using corn starch, sodium alginate, and Weissella confusa exopolysaccharide as wall material. The encapsulates produced presented a moisture content between 7.10 and 10.45% (w.b), a solubility of 53.06 ± 0.54%, and a wettability of 31.46 ± 2.02 s. The total phenolic content (TPC), antioxidant capacity of DPPH, and ABTS of the encapsulates were also determined, finding 232.55 ± 2.07 mg GAE/g d.m for TPC, 45.64 ± 0.9 µm Trolox/mg GAE for DPPH, and 51.69 ± 1.08 µm Trolox/mg GAE for ABTS. Additionally, ultrahigh performance liquid chromatography (UHPLC) analysis allowed us to identify and quantify six bioactive compounds: rosmarinic acid, caffeic acid, p-coumaric acid, ferulic acid, gallic acid, and quercetin. According to the above, using ionotropic gelation, it was possible to obtain microencapsulates containing bioactive compounds from pineapple peel extracts, which may have applications in the development of functional foods.

In this work, pineapple peel (PP) was reused as a precursor in biochar (BC) production at elevated temperatures (i.e., 500–900 °C) for residence times of 0–60 min. The findings showed that pyrolysis temperature and residence time played a vital role in pore development. As pyrolysis temperature increased from 800 to 900 °C for residence times of 20 and 60 min, the data on the Brunauer–Emmett–Teller (BET) surface area of the resulting biochar products significantly jumped from 11.98–32.34 to 119.43–133.40 m2/g. In addition, there was a significant increase in the BET surface area from 1.02 to 133.40 m2/g with the residence time of 0 to 20 min at 900 °C. From the data of the nitrogen adsorption–desorption isotherms and the pore size distribution, both micropores (pore diameters of <2.0 nm) and mesopores (pore diameters of 2.0–50.0 nm) are present in the PP-based biochar products. Due to its good fittings in the pseudo-second-order model and its hydrophilic nature, as seen in the Fourier transform infrared spectroscopy (FTIR), the resulting biochar could be a porous material to be used for the effective removal of cationic compounds (i.e., methylene blue (MB)) from liquid phases. [ABSTRACT FROM AUTHOR]

The study was conducted to determine the effect of breed and graded levels of sun-dried pineapple peel (PP) on the carcass characteristics of growing rabbit bucks. Thirty-two growing rabbits (New Zealand White, Chinchilla and Dutch) aged between 6 and 7 weeks, with an initial average weight of 762,25±52,66 g; were randomly assigned to four dietary treatments (0%, 5%, 10% and 15% PP) in a completely randomized 3 x 4 design involving three breeds and four dietary treatments, with eight rabbits of each breed in each treatment. The experimental diets and clean drinking water were supplied ad libitum during the experiment, which lasted 56 days. At the end of the feeding trial, three rabbits from each of the treatments were used for analysis of carcass characteristics. The carcasses were cut into parts, which were weighed. These were the head, loin, thoracic cage, skin, forelimb, shank, hind limb, testis, organs (heart, liver, kidney, caecum, lungs, stomach, and intestine), and abdominal fat. The data were subjected to statistical analysis in SAS software version 9.0. There were no significant (P > 0,05) differences in the weight of any of the organs or retail cuts except for the thoracic cage and shank, with significantly (P < 0,05) higher values in the Chinchilla breed. The results pertaining to the influence of graded levels showed no significant (P > 0,05) difference in any of the parameters except for the caecum, intestine and hind limb, with the highest weights at 10%, 0% and 5% PP, respectively. However, there were no differences and no deleterious effects across all treatments on all major carcass traits of growing rabbit bucks. In conclusion, the chinchilla breed is recommended due to the higher thoracic cage and shank weights, and 10% inclusion of pineapple because it resulted in higher caecum weight. [ABSTRACT FROM AUTHOR]

Antioxidant phenolic compounds were extracted from fermented samples of Golden pineapple peels via an ultrasound method. The fermentation conditions to maximize the production of phenolic content and antioxidant activity were previously determined (pH: 5.5, T: 37.3 °C and 85% moisture content). A central composite design with 20 treatments was applied to evaluate the effect of the ethanol concentration, time, and temperature on the production of phenolic compounds and antioxidant activity of the extracts. The statistical analysis showed that the optimal conditions to produce extracts with high phenolic content and antioxidant activity were: 62 °C, 30 min and 58% ethanol. We obtained 866.26 mg gallic acid equivalents (GAE)/g d.m in total phenolic content and for antioxidant activity expressed as percentage inhibition, 80.06 ± 1.02% for ABTS and 63.53 ± 2.02% for DPPH, respectively. The bioactive compound profile in the extracts was identified and quantified using ultra-high performance liquid chromatography (UHPLC), this method showed the presence of rosmarinic acid, caffeic acid, vanillic acid, p-coumaric acid, ferulic acid, quercetin-3 glucoside, rutine, quercetin, kaempherol-3 glucoside and gallic acid, demonstrating the great potential of these by-products to obtain components that can benefit the consumer's health. [ABSTRACT FROM AUTHOR]

Pineapple [Ananas comosus (L.) Merr.] has long been recognized as a source of bioactive compounds that are frequently used in health and wellness products. The benefits of pineapple, among others, include immunomodulatory and anti-inflammatory properties. This study aimed at evaluating the potential of phytochemical compounds in pineapple peel as immunomodulators and anti-inflammatory agents using an in silico approach. The phytochemical of the pineapple peel's n-hexane extract was analyzed using GC-MS (gas chromatography-mass spectrometry). The analysis of biological activities of the phytochemicals was performed using the PASS Online webserver. Computational toxicity estimation was performed using the ProTox II webserver. The drug-likeness of the compounds was analyzed using Lipinski's rule of five. Additionally, molecular docking of selected phytochemicals against the NLRP3 inflammasome was performed. The results suggested the presence of phytochemicals with immunomodulatory and antiinflammatory properties in the n-hexane extract of pineapple peel. This information can be used as a starting point in the search for natural-based drugs that are effective at alleviating inflammatory symptoms, as well as in immunomodulatory aspects. [ABSTRACT FROM AUTHOR]

Single-cell protein (SCP) is the term used for crude or pure protein derived from simple single or multi-celled microorganisms. Pineapple peel contains monosaccharides as much as 10.8% so that it can be used as a fermentation medium in single-cell protein production. The purpose of this study was to determine the effect of adding carbon sources of fructose and sucrose on pH, cell dry weight, and protein content in the manufacture of single-cell proteins. This study used a completely randomized design (CRD) with two factors, namely the addition of carbon (fructose, sucrose, and control) and fermentation time (24.48, and 72 hours). The data analysis used the variance test and the Duncan Multiple Range Test (DMRT) continued to test with a confidence level of 95%. The results showed that the addition of carbon to the media had a very significant effect on media pH, cell dry weight, and protein content. In the medium with the addition of fructose it has a pH of 3.81; dry weight 0.4203 grams; and protein content 69.08/L. Whereas in the media with the addition of sucrose, the pH was 4.33, the dry weight of the cells was 0.3385 grams, and the cells had a protein content of 85.55 mg/L. The addition of a fructose carbon source gave the cell dry weight more than the addition of carbon sucrose

The objective of this study was to investigate isotherm adsorption of carbon microparticles from pineapple peel waste. Carbon microparticles were prepared by carbonizing pineapple peel waste at 215-250°C and grinding using a saw-milling process. To investigate adsorption properties of carbon microparticles, experiments were done by evaluating adsorption of curcumin (as a model of adsorbate) in the ambient temperature and pressure under constant pH condition. To confirm the adsorption characteristics, carbon particles with different sizes (i.e., 100, 125, and 200 ?m) were tested, and the adsorption results were compared with several standard isotherm adsorption models: Langmuir, Freundlich, Temkin, and Dubinin- Radushkevich. To support the adsorption analysis, several characterizations (i.e., optical microscope, sieve test, and Fourier transform infrared analysis) were conducted. The adsorption test showed that the adsorption profile is fit to the Freundlich model for all variations, indicating the multilayer adsorption process on heterogeneous surfaces and interactions between adsorbate molecules. The results from other isotherm models also confirmed that the adsorption process occurs physically via Van der Waals force in binding adsorbate on the surface of adsorbent.

Abstract This study was conducted to evaluate the potential of pineapple peel (PP) and pineapple crown leaves (PCL) as the substrate for vanillic acid and vanillin production. About 202 ± 18 mg L−1 and 120 ± 11 mg L−1 of ferulic acid was produced from the PP and PCL respectively. By applied response surface methodology, the ferulic acid yield was increased to 1055 ± 160 mg L−1 by treating 19.3% of PP for 76 min, and 328 ± 23 mg L−1 by treating 9.9% of PCL for 36 min in aqueous sodium hydroxide solution at 120 °C. The results revealed that PP extract was better than PCL extract for vanillic acid and vanillin production. Furthermore, the experiment also proved that large volume feeding was more efficient than small volume feeding for high vanillic acid and vanillin yield. Through large volume feeding, about 7 ± 2 mg L−1 of vanillic acid and 5 ± 1 mg L−1 of vanillin was successfully produced from PP extract via Aspergillus niger fermentation.

The purpose of this study was to examine the effect of alkaline soaking time on the crude fiber and protein fractions of pineapple peel. The research consisted of two stages, the first stage was immersion of pineapple peel with husk ash water filtration concentration (FAAS) and different soaking times, and the second stage was about giving basic pineapple peel flour (TNKB) with different percentages in the ration. The first stage used a factorial completely randomized design consisting of FAAS concentration factors of 20%, 30%, and 40%, and immersion time factors of 0, 24, 48, and 72 hours. The second stage used a completely randomized design (CRD) with 0%, 5%, 10%, and 15% TNKB treatments in the ration. . The best reduction in fiber and crude protein fractions from alkaline soaking preparations will be given to broiler chicken feed rations. The result of immersion of 30% concentration with soaking time for 72 hours showed the best decrease for the fiber fraction. So that this processed pineapple skin flour can be given to broiler chicken feed rations. The results of the study concluded that the use of alkaline acidification of pineapple peel in rations could be used up to a level of 15% without affecting the performance of broiler chickens.

The large pineapple's consumption and processing have generated a massive amount of waste yearly, which requires adequate treatment measures to avoid damages to the environment. Pineapple peel is one of the main residues obtained from this fruit and a promising strategy to take advantage of its potential is using it for biosurfactant production due to the peel's rich composition in fermentable sugars and nutrients, such as potassium and magnesium that favor the Bacillus subtilis growth and biosurfactant excretion as well. The current research performed a central composite design (CCD) with four independent variables (glucose, pineapple peel, potassium, and magnesium), evaluating substrates' influence on the surface tension reduction rate (STRR) and the emulsification index (EI24). The results indicated that pineapple peel has the necessary potential to act as a partial substitute for glucose and salt nutrients, minimizing the costs of supplementing with exogenous minerals. The highest surface tension reduction rate (57.744%) was obtained at 2.18% glucose (w/v); 14.67% pineapple peel (v/v); 2.38 g/L KH2PO4; and 0.15 g/L MgSO4.7H2O; whereas to obtain the maximum predicted value for EI24 (61.92%) the medium was composed by 2.24% glucose (w/v); 12.63% pineapple peel (v/v); 2.53 g/L KH2PO4; and 0.29 g/L MgSO4.7H2O. [ABSTRACT FROM AUTHOR]

Objective: To determine the optimum pH at which the pineapple peel can adsorb the greatest amount of copper. Design/methodology/approach: Sorbent material. The size of the pineapple peel was reduced to 0.250 mm; it was chemically modified with 0.2 M NaOH and 0.2 M CaCl2. Point of zero charge (PZC). Six solutions were prepared with 0.5 g of sorbent in an aqueous medium (with a 3-8 pH range), they were stirred at 225 rpm for 48 h. The derivative method was used to plot the initial pH versus final pH, in order to determine the PZC. Copper adsorption. CuSO4 solutions were prepared in 2, 4, 6, 8 10 mg/L concentrations; 0.1 g of pineapple biomass was added adjusting the pH to 5. The solutions had a contact time of 0 to 24 h. Results: The pineapple peel had a 5.0 point of zero charge (PZC) value, which indicates that pH values higher than the PZC are required to obtain an adsorbent with a negatively charged surface and favor the copper adsorption. A 50% copper removal was obtained in all concentrations after a 1 h contact time. Limitations on study/implications: This research had no limitations. Findings/conclusions: The point of zero charge is a reliable parameter that allows the adsorption process to take place and provides a greater certainty to the metal adsorption process. Meanwhile, pineapple peel can be used as an adsorbent material, consequently reducing its accumulation in open dumps. [ABSTRACT FROM AUTHOR]