Complete Digestion Research Articles

Quantitative monitoring of galactolipid hydrolysis by pancreatic lipase-related protein 2 using thin layer chromatography and thymol-sulfuric acid derivatization

Galactolipids are the most abundant lipids on earth where they are mainly found in photosynthetic membranes of plant, algae, and cyanobacteria. Pancreatic lipase-related protein 2 (PLRP2) is an enzyme with galactolipase activity allowing mammals, especially herbivores, to digest this important source of fatty acids. We present a method for the quantitative analysis of galactolipids and galactosylated products resulting from their digestion by guinea pig PLRP2 (GPLRP2), using thin-layer-chromatography (TLC), thymol-sulfuric acid as derivatization reagent and scanning densitometry for detection. Thymol-sulfuric acid reagent has been used for the colorimetric detection of carbohydrates. It is shown here that the derivatization of galactosyl group from galactolipids by this reagent is not affected by the bound acyl glycerol, acyl chains length and number of galactose residues in the polar head. This allowed quantifying simultaneously the initial substrate and all galactosylated products generated upon the hydrolysis of monogalactosyl di-octanoylglycerol (C8-MGDG) by GPLRP2 using a single calibration with C8-MGDG as reference standard. The reaction products, monogalactosyl monooctanoyl glycerol (C8-MGMG) and monogalactosyl glycerol (MGG), were identified and quantified, MGG being recovered from the aqueous phase and analyzed by a separate TLC analysis. This method is therefore suitable to quantify the products resulting from the release of both fatty acids present in MGDG and thereby shows that PLRP2 can contribute to the complete digestion of galactolipids and further intestinal absorption of their fatty acids.

MaCPepDB: A Database to Quickly Access All Tryptic Peptides of the UniProtKB.

Protein sequence databases play a crucial role in the majority of the currently applied mass-spectrometry-based proteomics workflows. Here UniProtKB serves as one of the major sources, as it combines the information of several smaller databases and enriches the entries with additional biological information. For the identification of peptides in a sample by tandem mass spectra, as generated by data-dependent acquisition, protein sequence databases provide the basis for most spectrum identification search engines. In addition, for targeted proteomics approaches like selected reaction monitoring (SRM) and parallel reaction monitoring (PRM), knowledge of the peptide sequences, their masses, and whether they are unique for a protein is essential. Because most bottom-up proteomics approaches use trypsin to cleave the proteins in a sample, the tryptic peptides contained in a protein database are of great interest. We present a database, called MaCPepDB (mass-centric peptide database), that consists of the complete tryptic digest of the Swiss-Prot and TrEMBL parts of UniProtKB. This database is especially designed to not only allow queries of peptide sequences and return the respective information about connected proteins and thus whether a peptide is unique but also allow queries of specific masses of peptides or precursors of MS/MS spectra. Furthermore, posttranslational modifications can be considered in a query as well as different mass deviations for posttranslational modifications. Hence the database can be used by a sequence query not only to, for example, check in which proteins of the UniProt database a tryptic peptide can be found but also to find possibly interfering peptides in PRM/SRM experiments using the mass query. The complete database contains currently 5 939 244 990 peptides from 185 561 610 proteins (UniProt version 2020_03), for which a single query usually takes less than 1 s. For easy exploration of the data, a web interface was developed. A REST application programming interface (API) for programmatic and workflow access is also available at https://macpepdb.mpc.rub.de.

Facilitating enzymatic hydrolysis with a novel guaiacol-based deep eutectic solvent pretreatment

Herein, we established a novel deep eutectic solvent (DES) using lignin-derived guaiacol as hydrogen bond donor (HBD). The sole ChCl/guaiacol system was found to be inefficient for the fractionation of wheat straw (WS), while the incorporation of trace AlCl3 significantly facilitated the degradation of hemicellulose and lignin, resulting in a complete enzymatic digestibility of the pretreated WS. Further, this study revealed that the DES-degraded lignin was readily precipitated during the washing process, and thus hindered the enzymatic hydrolysis of poplar and bamboo (with hydrolysis yield of 42.03% and 71.67%, respectively). Alkali washing offers a possible approach to remove the precipitated lignin, after which a near 100% hydrolysis yield was also obtained for poplar and bamboo.

Ozone-Induced DNA Damage: A Pandora’s Box of Oxidatively Modified DNA Bases

Ozone is a major component of air pollution and carries potentially mutagenic and harmful affects to health. The oxidation of isolated calf thymus DNA (CT-DNA) led to the nearly quantitative loss of normal DNA 2'-deoxyribonucleosides in the following order: T > G > C ≫ A. The major modification of pyrimidines (T, C, and 5-methylcytosine (5mC)) was the corresponding 5-hydroxyhydantoin derivative after complete digestion of DNA to its component 2'-deoxyribonucleosides. The oxidation of 5mC was 2.5-fold more susceptible than C considering the relative mole fraction of 5mC to C in CT-DNA. Other common oxidation products of pyrimidines (e.g., 5,6-dihydroxy-5,6-dihydropyrimidines, the so-called pyrimidine 5,6-glycols) were formed with a lower yield than 5-hydroxyhydantoin derivatives. In addition, several common oxidation products of G were observed (e.g., 8-oxo-7,8-dihydroguanine (8oxoG)) albeit with relatively minor yields. The sum of individual products was notably less than the loss of 2'-deoxyribonucleosides from which they were derived. In a search for additional products, we discovered the formation of pyrimidine ring fragments, predominantly N-formamide and N-urea, which were measured as a dinucleotide next to a nonmodified nucleotide upon partial digestion of oxidized DNA. Interestingly, the latter fragments were also observed in dinucleotides containing 8oxoG, indicating the formation of tandem lesions during ozonolysis of DNA. The oxidation of DNA upon exposure to ozone can be explained by reactions of an intermediate ozonide. These studies underline the complexity of ozone-induced DNA damage and provide valuable information to assess the formation of this damage in cellular DNA.

In vitro evaluation of sugar digestibility in molasses

Beet and cane molasses mainly contain mono- di-, and tri-saccharides, composed by hexoses, as well as pentoses in traces. However, rationing software consider sugars as only one entity, with a rate of digestion ∼20% h−1. The aim of this initial study was to investigate and evaluate the in vitro digestion dynamics and rates of the sugar fraction in molasses. Three beet and three cane molasses were randomly selected from a variety of samples collected world-wide and digested via in vitro rumen fermentation, at 1, 2, 3, 4, 6, 8, and 24 h. Samples were then analysed with a specific enzymatic kit to quantify residual sucrose, glucose, fructose, raffinose, galactose, and arabinose. Complete disappearance of sucrose happened within 3 hours of incubation. Glucose and fructose were completely digested within 4-6 h, showing variability among samples. Even if not so representative, galactose showed a similar trend of digestion (97% digestion within 3-4 h). Raffinose was quite slower in cane molasses, while it was completely digested within 1 h in beet molasses. Arabinose, a pentose, never reached a complete digestion, and its fermentation dynamic was different compared to other sugars. Calculated rates of digestion for sucrose, glucose and fructose, most representative sugars in molasses, were higher than 50% h−1 in both cane and beet. Obtained results showed that sugar fraction in molasses may vary, and different sugars are rapidly fermented by rumen microbes. Modern rationing models should consider a modification of sugar rates of digestion, since the actual one appears too slow than those observed in vitro. Highlights Molasses are unique blends of several sugars Major sugars are digested in few hours Rationing software should consider a faster rate of digestion for different sugars

Dry-heat processing at different conditions impact the nutritional composition and in vitro starch and protein digestibility of immature rice-based products.

Immature grain represents a precious nutritional source in many rural Africa areas. To optimize processing of immature rice into pepeta (a traditional rice-flakes produced from immature rice grains), immature rice (TXD306 variety) harvested at 18 and 26 days after 50% heading were processed in the laboratory under different soaking (0 and 12 h) and roasting temperature (80, 100 and 120 °C) regimes. Riboflavin, nicotinic acid, nicotinamide and iron concentration increased with severity of roasting temperature, while thiamine has an opposite trend. Heating promoted the transformation of insoluble into soluble dietary fiber, increased lipid digestibility decreasing protein one, which showed the highest value when rice was roasted at 100 °C. Soaking before roasting significantly increased moisture and iron content while slightly increased riboflavin, nicotinic acid and nicotinamide when compared to unsoaked products. Among roasted products, starch digestibility increased with roasting temperature. Microstructure analysis indicated a complete loss of cell wall integrity in cooked rice, determining a complete starch and protein digestion while this is delayed in raw rice and roasted products. We concluded that roasting at 100 °C is the optimum temperature to produce pepeta of the highest protein digestibility and low starch digestibility. Soaking before roasting at 120 °C is best when retaining micronutrients is considered.

Complete enzymatic digestion of double-stranded RNA to nucleosides enables accurate quantification of dsRNA

The rapid growth of research focusing on RNA, especially for RNA interference applications, has created a need for a robust method that can accurately determine the concentration of long dsRNA. As it is difficult to find a source for pure dsRNA reference material, the most common method for quantitation is using a reversed-phase HPLC method to determine purity, which is linked to a calibration curve prepared by measurements obtained using UV absorbance at 260 nm. In this study we developed a nucleic acid digestion method that can digest both double- and single-stranded RNA and DNA to nucleosides. A reversed-phase HPLC/UV method was used to separate and quantitate the monomeric nucleosides. Using this method, we were able to calculate the absorptivity coefficient (proxy for the extinction coefficient) for dsRNA to be 45.9 ± 0.52 μg mL-1/A260. This value agrees with the one report we were able to find but uses an orthogonal method. Moreover, this study allowed us to understand that sequence design can dramatically change the extinction coefficient of the molecule. For molecules with ssRNA overhangs, we observed a 5% reduction in the calculated extinction coefficient.

Determination of Ca3(PO4)2 in Bone China by Microwave Digestion-ICP-AES

The establishment of a microwave digestion method with the advantages of simple operation and complete digestion to process samples has shown that, high sensitivity, wide linear dynamic range, good precision, fast analysis speed and many other advantages of ICP-AES technology for rapid determination of tricalcium phosphate in bone china. Through the use of different P2O5 content of phosphate rock and kaolin national standard material configuration standard working solution for matrix matching to eliminate matrix interference, the microwave digestion sample processing condition selection, coexisting ion interference, method precision, accuracy, and detection limit tests were carried out. The results showed that the detection limit of the newly established method for tricalcium phosphate is 0.011mg.L-1; the HCl-HNO3-HF-H2O2 mixed acid decomposition system dissolves the best samples; the interference of the test results through the matrix matching coexisting ion pair is small; The relative standard deviation (RSD) is 1.08%~4.64%, and the recovery rate of standard addition is 92.4%~107.9%. The established method has high accuracy and precision; the bone china samples are analyzed and compared with the conventional digestion national standard method The t test method is used to prove that the two methods are not significantly different from the test results.

A single-molecule counting approach for convenient and ultrasensitive measurement of restriction digest efficiencies.

Restriction endonucleases play a central role in the microbial immune system against viruses and are widely used in DNA specific cleavage, which is called restriction digestion, for genetic engineering. Herein, we applied digital cell-free protein synthesis as an easy-to-use orthogonal readout means to assess the restriction digest efficiency, a new application of digital bioassays. The digital counting principle enabled an unprecedentedly sensitive trace analysis of undigested DNA at the single-molecule level in a PCR-free manner. Our approach can quantify the template DNA of much lower concentrations that cannot be detected by ensemble-based methods such as gold-standard DNA electrophoresis techniques. The sensitive and quantitative measurements revealed a considerable variation in the digest efficiency among restriction endonucleases, from less than 70% to more than 99%. Intriguingly, none of them showed truly complete digestion within reasonably long periods of reaction time. The same rationale was extended to a multiplexed assay and applicable to any DNA-degrading or genome-editing enzymes. The enzyme kinetic parameters and the flanking sequence-dependent digest efficiency can also be interrogated with the proposed digital counting method. The absolute number of residual intact DNA molecules per microliter was concluded to be at least 107, drawing attention to the residual issue of genetic materials associated with the interpretation of nucleases' behaviors and functions in daily genetic engineering experiments.

Impact of Inoculant Sources on Feed in Vitro Fermentability and Digestibility

The aim of this research is to compare alternative inoculant source for in vitro rumen fermentation. In the first experiment, inoculant from fistulated cattle kept in LIPI and IPB (Fis1 and Fis2) and inoculant from Bogor municipality abattoir and IPB abattoir (Abo1 and Abo2) were tested for their pH, total bacterial count, and protozoal number using a complete block design with four replications. In the second experiment, the effect of the inoculant sources was tested on cornmeal (F1), soybean oil meal (F2), Napier grass (F3), and dairy cattle complete ration (F4) fermentability and digestibility including pH, VFA, NH3, IVDMD and IVOMD parameters. The results showed an unsignificant different protozoal number among inoculant sources. The pH of Fis2 rumen liquor was significantly lower (p<0.05) than others. The bacterial population was significantly higher (p<0.05) in Fis2 and Abo2 than Abo1, and Fis1. The inoculant pH after feed fermentability was not influenced by feed type but inoculant source with Fis1 was significantly higher (p<0.05) than Fis2, Abo2, and Abo1. The ammonia, VFA concentration, IVDMD, and IVOMD were influenced by interaction between inoculant sources and feed types. Although inoculant from cattle close to the laboratory (Fis2 and Abo2) were better in term of higher bacterial population, higher fermentability and digestibility for most type of feeds but other sources can be used in vitro study without differences in average fermentability and digestibility results.
 Key words: abattoir, fermentability, fistula, inoculant, in vitro

Wheat-based food form has a greater effect than amylose content on fermentation outcomes and microbial community shifts in an in vitro fermentation model

Starches with high amylose content resist complete digestion in the small intestine with a fraction (resistant starch) entering the large intestine, where it is fermented by the human gut microbiota resulting in perceived beneficial health effects. However, the effects of food form on the large intestinal digestion of products with different amounts of resistant starch are unknown. Here, wheat flours with 32%, 71%, 74% and 84% amylose content were used to prepare bread, tortillas and noodles, and after in vitro treatment simulating small intestinal digestion, were subjected to in vitro fermentation with a pooled human faecal inoculum. The results showed that food form rather than initial amylose content significantly affected both fermentation rates and short chain fatty acid (SCFA) production. Acetate concentrations were significantly greater in the noodle-based fermentations, whereas propionate concentrations were significantly greater in the tortilla-based fermentations (p < 0.05). Butyrate concentrations were also significantly increased for both the noodle and tortilla-based fermentations when compared to bread (p < 0.05). The microbial communities supported by these different food forms were examined by metagenomic sequencing (MGS) of fermentation samples collected over 48 h. Among the top 20 most abundant species, Enterococcus faecium was significantly increased by bread and tortilla, whereas Ruminococcus spp. and Faecalibacterium prausnitzii were increased for noodles. Although the amount of resistant starch reaching the large intestine is a relevant consideration in pursuit of promoting digestive health, our findings suggest that food form has a major influence on the gut microbiota that is reflected in substantive changes in SCFA profiles.

Dinoflagellate Host Chloroplasts and Mitochondria Remain Functional During Amoebophrya Infection.

Dinoflagellates are major components of phytoplankton that play critical roles in many microbial food webs, many of them being hosts of countless intracellular parasites. The phototrophic dinoflagellate Scrippsiella acuminata (Dinophyceae) can be infected by the microeukaryotic parasitoids Amoebophrya spp. (Syndiniales), some of which primarily target and digest the host nucleus. Early digestion of the nucleus at the beginning of the infection is expected to greatly impact the host metabolism, inducing the knockout of the organellar machineries that highly depend upon nuclear gene expression, such as the mitochondrial OXPHOS pathway and the plastid photosynthetic carbon fixation. However, previous studies have reported that chloroplasts remain functional in swimming host cells infected by Amoebophrya. We report here a multi-approach monitoring study of S. acuminata organelles over a complete infection cycle by nucleus-targeting Amoebophrya sp. strain A120. Our results show sustained and efficient photosystem II activity as a hallmark of functional chloroplast throughout the infection period despite the complete digestion of the host nucleus. We also report the importance played by light on parasite production, i.e., the amount of host biomass converted to parasite infective propagules. Using a differential gene expression analysis, we observed an apparent increase of all 3 mitochondrial and 9 out of the 11 plastidial genes involved in the electron transport chains (ETC) of the respiration pathways during the first stages of the infection. The longer resilience of organellar genes compared to those encoded by the nucleus suggests that both mitochondria and chloroplasts remain functional throughout most of the infection. This extended organelle functionality, along with higher parasite production under light conditions, suggests that host bioenergetic organelles likely benefit the parasite Amoebophrya sp. A120 and improve its fitness during the intracellular infective stage.

5-Hydroxymethylcytosine Glucosylation-Triggered Helicase-Dependent Amplification-Based Fluorescent Biosensor for Sensitive Detection of β-Glucosyltransferase with Zero Background Signal

β-glucosyltransferase (β-GT) catalyzes the glucosylation of 5-hydroxymethylcytosine (5-hmC) to enable the survival of bacteriophage and parasite in host cells, and it is a critical tool enzyme for 5-hmC assay. However, few methods are available for β-glucosyltransferase assay, and they usually have the drawbacks of radioactive contamination, high background, laborious procedures, and unsatisfactory sensitivity. Herein, we develop a new fluorescent biosensor with zero background signal for sensitive detection of β-GT activity based on 5-hmC glucosylation-triggered helicase-dependent amplification (HDA). The detection probe we designed may act as both a probe for β-GT recognition and a template for HDA amplification. The β-GT-catalyzed 5-hmC glucosylation can protect the detection probes from both the cleavage by MfeI restrictive enzyme and the digestion by exonucleases I and III. The remaining detection probes can subsequently act as the templates for exponential HDA amplification to generate numerous double-stranded DNA products, which can be easily detected by SYBR Green I in a label-free manner. The zero background can be achieved by efficient elimination of primer-dimer nonspecific amplification and complete digestion of nonglucosylated detection probes. This biosensor exhibits high sensitivity and good specificity, and it can be further used to analyze β-GT kinetic parameters and screen the inhibitors, providing a powerful platform for deeper understanding of β-GT biological functions and promoting β-GT-related epigenetic studies. Furthermore, this biosensor can be extended to detect various DNA-modifying enzymes by simply replacing the recognition sequence and restriction enzyme.

Comprehensive assessment of heavy metal pollution and ecological risk in lake sediment by combining total concentration and chemical partitioning.

Total concentration and chemical partitioning of heavy metals are commonly used in environmental quality assessment; however, their comparability and comprehensive application are far less discussed. Herein, bioavailability, pollution and eco-risk of As, Cd, Cr, Cu, Ni, Pb and Zn in surface sediments of Erhai Lake were evaluated referring to multiple indices following the experimental methods of complete digestion, optimized Community Bureau of Reference (BCR) and 1.0M HCl extractions. Results of bioavailability for most metals were similar and comparable from BCR and HCl extractions. While bioavailable concentrations of Cd and Pb from HCl extraction were significantly (p<0.01) lower than those from BCR extraction, indicating BCR extraction is more efficient. Results of enrichment factor (EF) and concentration enrichment ratio (CER) suggested that Cd was the highest polluted element followed by As, Pb and Zn, whereas Cr, Cu and Ni were mainly natural in origin. Similar concentrations of anthropogenic As from EF and CER assessments indicated anthropogenic As mainly existed in bioavailable form. However, anthropogenic Cd, Pb and Zn existed in both bioavailable and residue forms, resulting in the underestimation of anthropogenic metals by the CER assessment. The sediment quality guidelines (SQGs), potential ecological risk index (Er) and risk assessment code (RAC) showed inconsistent eco-risks for each of the metals except Cd. Combining pollution level and chemical partitioning with SQGs, Er and RAC assessments, high eco-risk of Cd, moderate eco-risk of As and Pb, and low eco-risk of Cr, Cu, Ni and Zn were graded. Our study highlights the limitation of single index and the necessity of integrating multiple indices following total concentration and chemical partitioning in metal pollution and eco-risk assessments.

KUALITAS BAHAN KERING DAN BAHAN ORGANIK PAKAN KOMPLIT FERMENTASI BERBASIS DAUN GAMAL SECARA IN VITRO

This study aims to determine the digestibility quality of dry matter and organic matter of complete fermented feed. This study used a completely randomized design with complete feed fermentation duration of 0 weeks, 3 weeks, 6 weeks and 9 weeks. The variables observed were the digestibility quality of dry matter and organic matter in vitro. The results showed that the dry matter digestibility of complete fermented feed at 0 weeks (48.508%) and 6 weeks (48.17%) was not significantly different (P> 0.05). Meanwhile, the complete dry matter digestibility of the fermentation time of 3 weeks (51.474%) and 9 weeks (44.558%) showed significant differences (P <0.05). Digestibility of complete feed organic matter with fermentation time of 0 weeks and 3 weeks did not show any difference but was significantly different from complete feed with 6 weeks and 9 weeks of storage. The conclusion of this study is the digestibility value of organic matter is higher than the value of dry matter digestibility because the digestibility of dry matter still contains ash and the digestibility of organic matter does not contain ash. Keyword : Complete Feed, Long Fermentation, In Vitro Digestibility

Review about Adhyashana as a causative factor in Grahanidushti from Charak Samhita.

ABSTRACT : Grahanidushti or Grahaniroga is associated with group of disorders caused due to Agnidushti. Grahani is an organ described in Ayurveda texts as a Sthana of Agni where the Agni is placed. Grahani and Agni are said to be inter-related i.e. if one gets vitiated it vitiates other too in long course of time. The Sthiti or state of Agni depends upon Ahara which is a major important part of life which is included in Trayopastambha (key pillars). For that Ayurveda broadly explains Ahara-Vidhi which is the rules and manners for preparing and having food. Vidhi-tyaga or not following these manners for long term give rise to Agnidushti which further give rise to Grahaniroga. One of these Vidhi-Tyaga hetu is Adhyashana which is having food before the digestion of previously ingested food. Ayurevda explains Jeernashana as a Vidhi which is to have food after the complete digestion of previous food. Incidence of Adhyashana has increased as increasing modernization of society. Also, the incidence of Grahaniroga has increased very much and both should be addressed. As the treatment for Grahaniroga is Agni-Vardhana or Deepana, Hetu- Privarjana i.e. avoiding causative factor is very important. To address this, an attempt is made to review Adhyashana in Grahanidushti.

A Microwave Digestion Technique for the Analysis of Rare Earth Elements, Thorium and Uranium in Geochemical Certified Reference Materials and Soils by Inductively Coupled Plasma Mass Spectrometry.

Two different digestion methods—microwave digestion (Mw) and Savillex digestion (Sx)—were used to evaluate the best quality control for analysis of the rare earth elements, Th and U in the geochemical certified reference material JSd-2, supplied by the Geological Survey of Japan (GSJ). The analysis of trace elements was carried out using inductively coupled plasma mass spectrometry (ICP-MS). The digestion recovery was > 90% for almost all elements by both methods. Mw-4 (four repeats of the microwave digestion) was found to be more effective and faster than Sx. In order to evaluate the efficiency of Mw-4, three other GSJ certified reference materials, JLk-1, JB-1 and JB-3, as well as five different soil samples from Belarus, Japan, Serbia and Ukraine were also analyzed. The Mw-4 method was seen to be promising for complete digestion and recovery of most of the elements. The U/Th ratio showed some heterogeneity for Ukraine and Serbia soils affected by Chernobyl nuclear power plant accident and depleted uranium contamination, respectively. This method can be successfully applied to any type of soils for elemental analyses.

Efficient biobutanol production by acetone-butanol-ethanol fermentation from spent coffee grounds with microwave assisted dilute sulfuric acid pretreatment

The integral valorization of potential sugars (cellulosic and hemicellulosic) from spent coffee grounds (SCG), a lignocellulosic residue, is proposed in this work. With this aim, the microwave assisted dilute sulfuric acid pretreatment has been optimized, leading to a hemicellulosic sugar recovery in the pretreatment liquid (HSRL) and an enzymatic hydrolysis yield of 79 and 98%, respectively, at 160.47 °C and 1.5% H2SO4. Moreover, the complete digestibility of cellulose (enzymatic hydrolysis yield = 100%) was also discovered for non-pretreated SCG, which is very interesting. Secondly, the production of biobutanol, an advanced biofuel, is also proposed from pretreated SCG enzymatic hydrolysate and pretreatment liquid achieved under optimal conditions. These were fermented by Clostridium beijerinckii, yielding 95 kg butanol/t SCG (dry matter) and 151 kg acetone-butanol-ethanol/t SCG (dry matter).

Effects of Esterified Maltodextrin on In Vitro Gastrointestinal Digestibility of Tween 80‐Stabilized Oil‐in‐water Emulsion

AbstractAmphiphilic esterified maltodextrin palmitate (DE9_P) is synthesized using an enzyme‐catalyzed reaction and exhibits both emulsifying and stabilizing activity. Native maltodextrin with a dextrose equivalent of nine (DE9) and DE9_P are applied in Tween 80‐stabilized oil‐in‐water emulsions. The effects of different DE9/DE9_P concentrations (10–50% w/w) on in vitro gastrointestinal digestibility of the Tween 80‐stabilized emulsions are investigated. After complete digestion, at a low DE9/DE9_P concentration (10% w/w), the released free fatty acid (FFA) content of the Tween 80‐stabilized emulsion containing DE9_P (13%) is much lower than that of the emulsion containing DE9 (33%) because of the synergistic Tween 80 and DE9_P stabilization layer. As the concentration increases to 30% w/w, the released FFA content increases for both systems containing DE9 and DE9_P. However, the emulsion system with DE9_P still has a lower content of released FFA than for DE9. Further increasing the concentration to 50% w/w results in a clear decrease in the released FFA content for both emulsions because the highly viscous continuous phase may cause less digestive reaction. The oil‐water interfacial stabilization layer and the viscosity of the intestinal digested system may be important factors in the enhancement or inhibition of lipid digestion.Practical Applications: The application of the potential ingredients at suitable concentrations enables the design and control of lipid digestibility and the texture of products to satisfy consumers’ needs. DE9_P may be an attractive alternative ingredient for emulsified foods because it can function both via synergistic emulsion stabilization with Tween 80 and via modification of textural characteristics as a stabilizer. Moreover, DE9_P has greater efficacy than DE9 in the inhibition of lipid digestibility of Tween 80‐stabilized oil‐in‐water emulsions.

Design of Solid state digester for biogas production from banana wastes

Processing of banana results in a huge amount of waste generation, leaves, stems and peels etc. Indiscriminate disposal of these wastes when decomposed produces noxious gases such as hydrogen sulphide and ammonia, which pose serious environmental hazards. Thus turning them into biomass feedstock offers a better waste management option and also source of energy production. For the past 30 years, there has been only biogas plants which are developed for treating cow dung as feed material. In those plants only other organic wastes are used as feed material. As banana wastes contain high moisture, they can be treated by the way of solid state digestion. The paper describes the design of solid state digester of 1 m3 capacity of biogas production, exclusively for treating banana wastes by the method of solid state anaerobic digestion. The reactor was designed based on the hydraulic retention time and the total solid content of the banana feedstock in order to complete digest and produce biogas at a faster rate with optimum quantity and methane content. The digester was designed for a feed capacity of 30 kg with 30 days retention time with a gas holder volume of 1 m3. The diameter and height of the digester are 1.09 m and 2.1 m and for gas holder the diameter and height are 1.01 m and 0.9 m respectively. The developed digester was found to convert 90% of the solid content in feed to bioenergy.