High Carbohydrate Content Research Articles

Fermented Sugar From Ultrasound-Assisted Acid Hydrolysis Berenuk Fruit (Crecentia Cujete L.)

Berenuk fruit (Crecentia Cujete L) is a non-food plant often found in tropical areas. Berenuk has quite a high content of carbohydrates and its derivatives. Among them are 18.61% carbohydrates, 59.86% sucrose, 25.09% fructose, and 18.24% galactose, so berenuk fruit has the potential to be a source or ingredient for bioethanol. The bioethanol process from biomass goes through several steps: raw material preparation, hydrolysis process and fermentation. The hydrolysis process is the process of breaking down carbohydrate into glucose units which are connected by β-1,4 glycosidic bonds. Another method of breaking sugar polymers can be done using alternative energy such as ultrasonic waves (50Hz, 50W) or microwaves. In this research, an ultrasonic-assisted acid hydrolysis process was carried out. The type of acid used is concentrated sulfuric acid (H2SO4). Ingredients ratio 1:20 (w/v) berenuk powder sample with sulfuric acid. The sulfuric acid concentrations used were 1 M, 2 M, and 3 M. Hydrolysis times were 40 minutes, 60 minutes, and 80 minutes at a temperature of 1000C. The results of research that has been carried out on the preparation process of bereneuk fruit have an average water content of 97.44%, so treatment is required before proceeding to the hydrolysis and fermentation process, namely by drying the drying process is carried out directly in sunlight for seven days, then continued by heating the oven for 8 hours at 1000C. In the ultrasonic wave assisted hydrolysis process carried out at a H2SO4 concentration of 3 M, a hydrolysis time of 80 minutes, and a temperature of 1000C produces 22.20% glucose.

Sorghum starch: Extraction, characterization and film development

Sorghum starch was extracted from sorghum grain (24.27 % average yield) and had a high carbohydrate content (86.66 %), indicating its high purity. This starch was used for the production of films with different concentrations of sorghum starch (2, 3 and 4 %) and glycerol (20, 30 and 40 g/100 g of starch). Most films were homogeneous and practically amorphous; however, the micrographs revealed the presence of some starch granules. These films also had relevant barrier properties to ultraviolet light, with infrared spectrum characteristic of sorghum starch, high lightness (L* = 87.77–90.19) and a tendency of color for the pink, but with low intensity of hue (h° = 297.06–315.20; chroma = 7.00–9.47). Thickness varied from 0.048 to 0.081 mm and the water solubility from 27 % to 48 %. Thermogravimetric analysis revealed the existence of three thermal events, correspondents to the elimination of water, decomposition of glycerol and starch, respectively. The glass transition temperature decreased with increasing glycerol content, keeping in range of 9–15°C. The film with the best mechanical performance was the one composed of 4 % starch and 30 g/100 g glycerol, as it presented a tensile strength of 3.63 MPa and elongation of 44.10 %. Water vapor permeability varied from 5.504 a 14.234 g.mm.m−2.dia−1.kPa−1, due to the increase in the concentrations of starch and glycerol. The characterization directed the usage of such films to pack vegetables and, therefore, proved that the sorghum starch is a promising source for the production of biodegradable films.

KARAKTERISTIK KIMIA DAN SENSORI KUKIS BERBAHAN BAKU TEPUNG MOCAF DENGAN TAMBAHAN PUREE JAGUNG KUNING

Mocaf (Modified Cassava Flour) is flour from modified cassava. Mocaf flour has a high carbohydrate content so it is necessary to add other nutritional sources to enrich the product produced. Corn puree is an alternative for producing cookies with high nutritional value. The aim of this research was to determine the best concentration of mocaf cookies with the addition of sweet corn puree. The parameters tested are proximate and sensory tests. The design used was a Completely Randomized Design (CRD) with 1 factor, namely the concentration of corn puree. The analysis results obtained were that the treatment of adding sweet corn puree (20%) was the best addition of sweet corn puree. The chemical test results were water content 1.96%, ash content 2.24%, fat content 17.95%, and protein content 4.34%. In contrast to the carbohydrate content, the best treatment for sweet corn puree (0%) is the carbohydrate content of 77.22%. The results of the sensory test showed that the panelists showed a tendency to like the research cookies.

Assessment of the physicochemical, functional and structural characteristics of a defatted flour from guamuchil (Pithecellobium dulce (Roxb.) seeds

Guamuchil tree is native of México and its fruits, which belong to Leguminosae family, contain seeds that are wasted. In this work, the physicochemical, functional and structural characterization of a defatted flour obtained from guamuchil seeds (DGuSF) was carried out. DGuSF had a low moisture (5.44 %) and lipid (2.91 %) contents and high protein (33.18 %) and carbohydrate (55.54 %) contents. Functional properties were highly dependence of pH, showing the highest values of 4.71 g H2O/g, 50 %, 84 %, 56 %, and 79 % for water binding capacity (WBCa), emulsifying capacity (EmA), emulsifying stability (EmS), foaming capacity (FoC), and foaming stability (FoS), respectively, at a value of 10. In the case of least gelling concentration (LGCo) the better value of 8 % was at pH 4, being obtained at this same condition the highest apparent viscosity (ηa) of 290.8 Pa·s. Values of 72.3 % and 40.5 % for in vitro protein enzymatic digestibility (IVPED) and in vitro antioxidant activity (IVVA), respectively, were also obtained for DGuSF, while their protein fractions presented molecular masses in the scale of ∼13–150 kDa. According to these results, guamuchil seeds could represent an alternative for the elaboration of DGuSF, to be applied as a food constituent because of its good compositional and functional characteristics.

Daily intake of baru (Dipteryx alata Vog.), a Cerrado native almond, promotes changes in the intestinal microbiota of individuals with obesity: A pilot study

The Brazilian Cerrado biome is rich in plant biodiversity, with fruits that have unique sensory characteristics and high nutritional quality. Among the various fruits, baru (Dipteryx alata Vog.) has attracted the attention of researchers because of its high lipid, protein, carbohydrate, fiber, and micronutrient (minerals and vitamins) contents. The present study evaluated the effects of regular consumption of baru almonds for over 60 days on the biochemical and anthropometric profiles and fecal microbiota of obese individuals. A pilot study was conducted on 15 individuals with obesity who were instructed to consume a 20-gram portion of baru almonds throughout the day. The body composition was assessed using anthropometric measurements. Blood pressure, glucose levels, lipid profile, serum insulin and iron contents, and fecal microbiota composition were determined at baseline (day 0) and after 60 days. Baru almond consumption contributed to changes in biochemical parameters, improved HDL cholesterol levels, and reduced total and LDL cholesterol levels. Some positive changes in the microbiota composition after consuming baru almonds include a decrease in the Faecalibacterium family and an increase in the Provotella genus. Therefore, ingesting baru almonds can modulate gut microbiota of individuals with obesity.

Utilization of carbon catabolite repression for efficiently biotransformation of anthraquinone O-glucuronides by Streptomyces coeruleorubidus DM.

Carbon catabolite repression (CCR) is a highly conserved mechanism that regulates carbon source utilization in Streptomyces. CCR has a negative impact on secondary metabolite fermentation, both in industrial and research settings. In this study, CCR was observed in the daunorubicin (DNR)-producing strain Streptomyces coeruleorubidus DM, which was cultivated in high concentration of carbohydrates. Unexpectedly, DM exhibited a high ability for anthraquinone glucuronidation biotransformation under CCR conditions with a maximum bioconversion rate of 95% achieved at pH 6, 30°C for 24 h. The co-utilization of glucose and sucrose resulted in the highest biotransformation rate compared to other carbon source combinations. Three novel anthraquinone glucuronides were obtained, with purpurin-O-glucuronide showing significantly improved water solubility, antioxidant activity, and antibacterial bioactivity. Comparative transcript analysis revealed that glucose and sucrose utilization were significantly upregulated as DM cultivated under CCR condition, which strongly enhance the biosynthetic pathway of the precursors Uridine diphosphate glucuronic acid (UDPGA). Meanwhile, the carbon metabolic flux has significantly enhanced the fatty acid biosynthesis, the exhaust of acetyl coenzyme A may lead to the complete repression of the biosynthesis of DNR, Additionally, the efflux transporter genes were simultaneously downregulated, which may contribute to the anthraquinones intracellular glucuronidation. Overall, our findings demonstrate that utilizing CCR can be a valuable strategy for enhancing the biotransformation efficiency of anthraquinone O-glucuronides by DM. This approach has the potential to improve the bioavailability and therapeutic potential of these compounds, opening up new possibilities for their pharmaceutical applications.

PROXIMATE ANALYSIS AND MINERAL PROFILE OF TARO (Colocasia esculenta) IN EMBU, KENYA

<p><strong>Background.</strong> Taro (<em>Colocasia esculenta</em>) is one of the underutilized crops in Kenya, grown under a wide range of environmental and edaphic conditions. This crop has exceptional dietary value and numerous culinary applications due to its edible leaves and corms. However, the mineral nutrient composition of taro in Kenya is still not well known due to a lack of scientific information concerning production. <strong>Objective. </strong>To determine the proximate composition and mineral profile of taro under different watering regimes and planting densities in Embu, Kenya. <strong>Methodology.</strong> A study was conducted at the Kenya Agricultural and Livestock Research Organization (KALRO) – Embu Research Centre, during the long rains (LR) 2021, and short rains (SR) 2021/2022. A factorial experiment with a split-plot layout arranged in a completely randomized block design was adopted. The watering regimes (100 %, 60 %, and 30 % based on the field capacity (FC)) were the main factor while the sub-factor was the planting density, with three replications. The planting densities used were 0.5 m × 0.5 m (40,000 plants ha<sup>-1</sup>), 1 m × 0.5 m (20,000 plants ha<sup>-1</sup>), and 1 m × 1 m (10,000 plants ha<sup>-1</sup>), representative of high, medium, and low planting densities respectively. Proximate analysis and mineral content were determined. <strong>Results.</strong> Significant differences (<em>P < 0.05</em>) in seasons were noted for protein, fibre, potassium, calcium, sodium, and zinc in the taro corms. The high carbohydrate content observed in this study (35 – 39 %) indicates that taro tubers are a good source of nutritional energy. Potassium (> 5000 mg kg <sup>-1</sup>) and magnesium (> 1000 mg kg <sup>-1</sup>) were the most prevalent mineral elements in taro corms and leaves, with copper (< 25 mg kg <sup>-1</sup>) being the least prevalent. <strong>Implications.</strong> Consumption of nutrient-rich foods such as taro helps the body to utilize the necessary nutrients to combat malnutrition and promote food security in rural communities. <strong>Conclusion.</strong> Taro leaves can be recommended as leafy vegetables as they are good sources of potassium, magnesium, calcium, manganese, iron, copper, and zinc; and the corms have low fat and protein content, high calorific energy, and high carbohydrate content. Taro represents one of the main sources of energy in many parts of the tropics and its production can be recommended in sub-humid areas in Kenya.<strong></strong></p>

The proximate composition and phytochemical screening of Momordica Balsamina (balsam apple) fruit and leaves

Malnutrition is a global issue that affects both children and adults irrespective of their socio-economic status. It is therefore important to find various means to tackle malnutrition. This is especially important as undernutrition and overnutrition can be linked to a variety of non-communicable diseases (NCDs). Therefore, this study aimed to gather more insight into the nutritional and phytochemical quality of Momordica balsamina leaves and fruit (fruit pericarp, fruit flesh and seeds). The results showed that M. balsamina had a nutritional composition that would be advantageous to the human diet. The nutritional quality was verified by the presence of a high protein percentage across all samples (19.72–29.08%), with the leaves containing the highest protein content (29.08% ± 0.77). There was also a low-fat content present across all samples which ranged from 1.03% to 2.40%. The ash content indicated the presence of total minerals to be adequate (2.93–21.16%), where the pericarp had the highest ash quantity (21.16% ± 0.09). Overall, the moisture levels were low (7.11–13.40%); with M. balsamina seeds containing the highest carbohydrate content (67.84% ± 0.30). Moreover, rich in the major phytoconstituents, M. balsamina extracts were found to contain alkaloids, saponins, cardiac glycosides, steroids and triterpenoids. Based on these findings, it can be deduced that the incorporation of M. balsamina into an individual’s diet could prevent diseases associated with malnutrition and could be used to supplement the human diet in managing certain NCDs.

Nutritional Composition and Safety Aspects of Deep-Sea Whelks (Buccinum tenuissimum Kuroda).

The deep-sea whelk Buccinum tenuissimum Kuroda is highly sought-after as food in East Asian countries, notably, Korea and Japan. However, it lacks official recognition as a food product in Korea. This study aimed to assess its nutritional composition and safety for the potential development of seafood products. The nutritional analysis revealed high protein (13.54-20.47 g/100 g whelk), fat (0.85-8.59 g/100 g whelk), carbohydrate (1.55-12.81 g/100 g whelk), and dietary fiber (1.25-1.95 g/100 g whelk) contents in both muscle and gut samples, with energy contents ranging from 339.11 ± 1.64 to 692.00 ± 3.21 kJ/100 g. Key minerals, including iron, potassium, calcium, and sodium, and essential fatty acids, including eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid, omega-3, and omega-6 fatty acids, were abundant, making it a potential supplementary food. Notably, heavy metal levels met the Korean standards for seafood safety. No trans fats, radioactivity concerning the radioactive isotopes 134Cs/137Cs and 131I, or pathogenic bacteria were detected. This confirms the safety and nutritional value of deep-sea whelks, suggesting their potential for developing seafood products rich in beneficial components, which could enhance nutrition and food security while contributing to economic growth.

Metabolomic profiling, nutritional parameters and potential bioactive metabolites of the edible mushroom Tricholoma mesoamericanum

SummaryEdible Mushrooms boast a diverse array of biomolecules with exceptional nutritional and bioactive benefits for humans. This study conducted metabolomic and nutritional analyses, aiming to identify potential bioactive metabolites in Tricholoma mesoamericanum from Pinus forests in Veracruz, Mexico. These mushrooms exhibited high carbohydrate and protein contents, coupled with a significant anti‐oxidant capacity. Metabolomic analysis identified 181 different compounds, with terpenoids, fatty acids, glycerophospholipids, and sphingolipids as the most enriched compound classes detected in T. mesoamericanum. Some compounds presented a positive correlation, while others demonstrated negative correlations with anti‐oxidant activity, ash, carbohydrate, fat, and protein contents. Notably, 39 of these compounds have previously demonstrated medicinal properties in other mushroom species, suggesting potential health benefits for humans. This study presents the first combined nutritional and metabolomic analysis of T. mesoamericanum, highlighting its value and underscoring the importance of sustainable management and further research to explore its bioactive potential, as unveiled in this investigation.

Karakteristik Organoleptik Selai Kacang Merah (Phaseolus vulgaris L) dengan Variasi Penambahan Gula Pasir

Indonesia has many types of nuts with various colors, varieties, and shapes, which have great potential to add variety and nutrition to different patisserie products. One of them is red beans (Phaseolus Vulgaris L), which is a type of legume that has the highest carbohydrate content, protein content equivalent to green beans, much lower fat content than soybeans and peanuts and is also often used as an ingredient in making jam. This research aims to determine the appropriate sugar concentration on the organoleptic characteristics of red bean butter. The research was designed using a single factor. A completely randomized design with additional sugar concentration treatment consisting of 3 treatment levels of 30, 40, and 50%. The research results show that the addition of 50% sugar concentration is the best concentration based on the results of organoleptic tests, which include hedonic tests, like color (2.64), like taste (3.04), like texture (3.24), like aroma (3.24), Overall like is close to very like (3.64). Hedonic quality test for chocolate color (3.08), red bean aroma (3.36), soft texture (3.28), and red bean taste (3.24).

Physicochemical properties of wild and cultivated Saccharina latissima macroalgae harvested in the Canadian boreal-subarctic transition zone

Saccharina latissima is a brown seaweed used as a food ingredient. The aim of this work was to study possible differences between S. latissima chemical composition, color, mode of cultivation, harvesting period and site and its environmental conditions. Water temperature, salinity, radiation, and fluorescence were monitored in each harvesting site. Chemical composition of S. latissima varied greatly with period and site, with a high content of carbohydrates and ash. Crude protein content varied from 3.7 % to 12.8 %, with a higher concentration observed in wild samples harvested in Bas-St. Laurent (11.1–12.8 %). Cultivated seaweed also presented a high crude protein (12.2 %) and ash (52 % against 27 % in wild samples) concentrations, but crude fiber and carbohydrates concentrations were lower, reaching up to 2.7 and 1.9-fold, respectively, than those in wild seaweeds. S. latissima presented a more intense yellow color in June. A trend of darker and more green-colored seaweeds when cultivated in the end of summer was confirmed. Our results suggest that variations in chemical components and chromaticity of this species are probably affected by complex interactions of environmental conditions.

Perbedaan Kandungan Fisikokimia Dan Karakteristik Pempek Berbahan Ikan Nila, Bayam, Daun Kelor dan Kalakai Sebagai Alternatif Makanan Tambahan Ibu Hamil Kurang Energi Kronik (KEK)

The problem of undernutrition during pregnancy is still a focus of attention, these problems include anemia and Chronic Energy Deficiency (CED). CED can have a negative impact on the mother and the fetus. One way to meet nutritional needs is to provide additional food. This study aims to find out the Physicochemical Contents and Characteristics of Pempek Made from Tilapia Fish, Moringa Leaves, Spinach and Kalakai as an Alternative Food Supplement for Pregnant Women with Choronic Energy Deficiency.The proportion for making pempek was made by adding 60% tilapia fish and 40% spinach, moringa or kalakai leaves. The data collected in this study were physicochemical characteristics (carbohydrates, protein, fat, crude fiber, ash, and moisture content) obtained from laboratory tests, sensory characteristic tests (color, flavor, texture, and taste) obtained by organoleptic tests using the hedonic method scoring scale. The results showed that there were differences in the color parameters (p=0,009), aroma (0,001), taste (0,001), and texture (0,008). The results of the proximate analysis showed that the highest carbohydrate content was in pempek tilapia kalakai (37,82 g), the highest protein content was in pempek tilapia moringa leaves (9,79 g), and the highest fiber content was in pempek tilapia spinach (0,7 g) and the iron content was highest in pempek tilapia moringa leaves (2,8 mg). In the preference level test, the highest score was obtained for pempek tilapia spinach with an average value of 0,626. Pempek tilapia kalakai spinach ang moringa leaves can be used as alternative snacks for pregnant women to prevent the birth of stunted.

The Effect of the Ratio of Rice Flour and Breadfruit Starch (Artocarpus communis) on the Characteristics of Cendol

Breadfruit is a fruit that grows widely in Indonesia. The use of breadfruit is still very limited, namely fried or boiled as a snack. Breadfruit has a high carbohydrate content, resulting in quite a lot of starch extraction. One way to increase the use of breadfruit is to process it into breadfruit starch. Breadfruit starch has a high amylose and amylopectin content so it can be used as a chewing agent in cendol production. The aim of this research is to obtain the ratio of breadfruit starch in making cendol, by testing water content and total dissolved solids. The data obtained were analyzed using One Way Anova and to determine whether there were differences in treatment, it was continued with the Duncan Multiple Range Test (DMRT) with a significance level of 5%. The results of the research show that the correct ratio in making cendol to substitute breadfruit starch would be 25% rice flour and 75% breadfruit starch. The addition of breadfruit starch to making cendol has a significant effect on the water content of 81.37% -84.45%. The addition of breadfruit starch did not significantly differ from the total amount of dissolved solids with a value of 6.33-6.67 brix.

Chemical Composition Study of Three Varieties of Date seeds (Iraqi, Saudi and Yemeni) and their Utilization as caffeine-free coffee alternative

The study aimed to investigate the chemical composition of three widely available types of date seed in the Yemeni market (Iraqi, Saudi, and Yemeni) and their potential use as caffeine-free coffee alternative. Quantitative estimation was conducted for moisture, ash, protein, fiber, fat, carbohydrates, and caffeine, along with a descriptive estimation for alkaloids, tannins, and resins. Date seed coffee was prepared and sensory evaluation was performed by trained panelists. The results showed that Yemeni date seeds had the highest extraction Rate on average (30%), while Saudi date seeds had higher moisture, protein, fat, and fiber contents on average (8.997, 6.897, 11.167, and 16.333%, respectively). Yemeni date seeds contained the highest carbohydrate content on average (58.290%). All tested date seeds were caffeine-free, while the chemical composition for Yemeni coffee were 7, 0.9, 13.9, 14.4, 12.8, 4.1, and 1.5% for moisture, ash, protein, fat, fiber, carbohydrates, and caffeine, respectively. Descriptive estimation results showed the absence of alkaloids in all date seeds and coffee samples, with the presence of both tannins and resins. For sensory evaluation indicated high values for all attributes of date seeds coffee alternative, with Saudi date seeds coffee outperforming other types, suggesting its potential use as a caffeine-free coffee alternative and its associated health benefits.

Third-generation D-lactic acid production using red macroalgae Gelidium amansii by co-fermentation of galactose, glucose and xylose

Macroalgae biomass has been considered as a promising renewable feedstock for lactic acid production owing to its lignin-free, high carbohydrate content and high productivity. Herein, the D-lactic acid production from red macroalgae Gelidium amansii by Pediococcus acidilactici was investigated. The fermentable sugars in G. amansii acid-prehydrolysate were mainly galactose and glucose with a small amounts of xylose. P. acidilactici could simultaneously ferment the mixed sugars of galactose, glucose and xylose into D-lactic acid at high yield (0.90 g/g), without carbon catabolite repression (CCR). The assimilating pathways of these sugars in P. acidilactici were proposed based on the whole genome sequences. Simultaneous saccharification and co-fermentation (SSCF) of the pretreated and biodetoxified G. amansii was also conducted, a record high of D-lactic acid (41.4 g/L) from macroalgae biomass with the yield of 0.34 g/g dry feedstock was achieved. This study provided an important biorefinery strain for D-lactic acid production from macroalgae biomass.

Sustainable energy enhancement strategy from Chlorella vulgaris microalgae biomass resource

ABSTRACT Growing demand for renewable and sustainable energy sources has prompted research into bioethanol production as a viable alternative to hydrocarbon fuel for automobile engines. Based on their high carbohydrate content, Chlorella vulgaris microalgae were chosen for this study as a feasible biomass for bioethanol synthesis. After conducting microwave-based acid hydrolysis with varying acid concentrations of sulfuric acid (H2SO4) for 1–15 min, this study found that 3% H2SO4 for 5 min yielded the highest yield of reducing sugar (6.77 g/L). In this work, the RSM approach of central composite design (CCD) was utilized for modeling and optimization of ethanol fermentation and the MATLAB Simulink approach was employed for the simulation of ethanol fermentation. This study compared the effects of using Saccharomyces cerevisiae yeast for fermentation at different fermentation times (12 to 48 h), temperatures (28 to 32°C), and size of inoculum (0.5–1.5 g/L). Based on the actual and predicted results, the best conditions for fermentation were 36 h of time, 30°C of temperature, and 1.5 g/L of inoculum size. This gave the maximum ethanol concentration of 3.31 g/L. Furthermore, the RSM method provides minimum error and maximum R2 value results for ethanol production compared to MATLAB simulation prediction (MSP). In addition, residue biomass from biofuel production is evaluated for its suitability for a further form of biofuel production. This research explores the opportunities for zero-waste biomass utilization in the development of biofuels.

Development of a Fermented Probiotic Beverage Inoculated with Kefir Grain

Background: Probiotics are live microorganisms that confer to have health benefits when consumed directly or processed. Regular administration of Probiotics would help in improving the gut microflora that has gained importance as bacteriotherapy which prevents the gastro-intestinal disease caused by pathogenic microorganisms. Vegans who are allergic or intolerant to dairy products can have the benefits of organic acids that are produced through fermentation. The present study was carried out to know the benefits of fermented products using kefir grains and fruits. Methods: The fermented product was tested for the evaluation of flavours, sensory, and shelf life which seemed to be very promising. In context to biomolecules, the product had a high concentration of absorbable protein, carbohydrate, antioxidant, and antibacterial properties. Result: The production of fermented beverages of certain fruits on a large scale, and its consumption may promote additional health benefits. The kefir beverage that is produced in this work may help to fill the gap between actual and innovative consumption of the fruits and kefir that may be recommended in the human diet with concern for their health.

Pengaruh Perlakuan Awal terhadap Karakteristik Bioetanol dari Limbah Kulit Singkong Karet (Manihot glaziovii)

Rubber cassava peel waste (Manihot glaziovii) has a high carbohydrate content, so it is feasible to convert it into bioethanol. In general, bioethanol production consists of four steps, pretreatment, hydrolysis, fermentation, and purification. The purpose of this study was to determine the suitable treatment for obtaining bioethanol with the finest characteristics from rubber cassava peel using three treatment variations, the pretreatment process with variations in the dissolving ratio of sodium hydroxide (NaOH) 0.5 M of 1:10; 1:12.5; and 1:15 (w/v), the hydrolysis process with various concentrations of sulfuric acid (H2SO4) of 0.15 N; 0.30 N; and 0.45 N, and the fermentation process with variations in the fermentation time for 3 days, 7 days, and 9 days. Based on the research results, the highest glucose content was 0.91%, with variations in dissolving NaOH 0.5 M 1:15 (w/v) in the pretreatment process and variations in the concentration of 0.30 N H2SO4 in the hydrolysis process, while the highest ethanol content was 68.05% at a fermentation time of 7 days.

Differential utilisation of subcellular skeletal muscle glycogen pools: a comparative analysis between 1 and 15min of maximal exercise.

In skeletal muscle, glycogen particles are distributed both within and between myofibrils, as well as just beneath the sarcolemma. Their precise localisation may influence their degradation rate. Here, we investigated how exercise at different intensities and durations (1- and 15-min maximal exercise) with known variations in glycogenolytic rate and contribution from anaerobic metabolism affects utilisation of the distinct pools. Furthermore, we investigated how decreased glycogen availability achieved through lowering carbohydrate and energy intake after glycogen-depleting exercise affect the storage of glycogen particles (size, numerical density, localisation). Twenty participants were divided into two groups performing either a 1-min (n=10) or a 15-min (n=10) maximal cycling exercise test. In a randomised, counterbalanced, cross-over design, the exercise tests were performed following short-term consumption of two distinct diets with either high or moderate carbohydrate content (10 vs. 4gkg-1 body mass (BM) day-1) mediating a difference in total energy consumption (240 vs. 138gkg-1 BM day-1). Muscle biopsies from m. vastus lateralis were obtained before and after the exercise tests. Intermyofibrillar glycogen was preferentially utilised during the 1-min test, whereas intramyofibrillar glycogen was preferentially utilised during the 15-min test. Lowering carbohydrate and energy intake after glycogen-depleting exercise reduced glycogen availability by decreasing particle size across all pools and diminishing numerical density in the intramyofibrillar and subsarcolemmal pools. In conclusion, distinct subcellular glycogen pools were differentially utilised during 1-min and 15-min maximal cycling exercise. Additionally, lowered carbohydrate and energy consumption after glycogen-depleting exercise altered glycogen storage by reducing particle size and numerical density, depending on subcellular localisation. KEY POINTS: In human skeletal muscle, glycogen particles are localised in distinct subcellular compartments, referred to as intermyofibrillar, intramyofibrillar and subsarcolemmal pools. The intermyofibrillar and subsarcolemmal pools are close to mitochondria, while the intramyofibrillar pool is at a distance from mitochondria. We show that 1min of maximal exercise is associated with a preferential utilisation of intermyofibrillar glycogen, and, on the other hand, that 15min of maximal exercise is associated with a preferential utilisation of intramyofibrillar glycogen. Furthermore, we demonstrate that reduced glycogen availability achieved through lowering carbohydrate and energy intake after glycogen-depleting exercise is characterised by a decreased glycogen particle size across all compartments, with the numerical density only diminished in the intramyofibrillar and subsarcolemmal compartments. These results suggest that exercise intensity influences the subcellular pools of glycogen differently and that the dietary content of carbohydrates and energy is linked to the size and subcellular distribution of glycogen particles.