High Temperature Short Time Treatment Research Articles

Decoding the Effects of High Hydrostatic Pressure and High-Temperature Short-Time Sterilization on the Volatile Aroma Profile of Red Raspberry Juice.

The loss of distinctive aromas due to sterilization significantly hinders efforts to enhance the sensory quality of fruit and vegetable juices. This study aimed to elucidate the impacts of high-hydrostatic pressure (HHP) and high-temperature short-time (HTST) sterilization methods on the loss of C6 aldehyde aroma-active compounds in red raspberry juice. External standard quantification and quantitative descriptive analysis (QDA) revealed a notable decline in the levels of hexanal and (Z)-3-hexenal following the HHP and HTST treatments (p < 0.05), resulting in a marked attenuation of the grassy aroma characteristic of red raspberry juice. Furthermore, a comprehensive examination of the precursors, pivotal enzymes, intermediates, and downstream aromas within the fatty acid metabolism pathway in different raspberry juice samples indicated that the C6 aldehydes loss induced by HHP and HTST sterilizations was primarily ascribed to the competitive inhibition of β-oxidation and the hindered enzymatic oxidation of fatty acids. These insights suggest that modifying sterilization protocols and enhancing enzymatic stability may help preserve the aroma integrity of raspberry juice. Our findings offer practical guidance for optimizing juice processing techniques to maintain flavor.

Continuous-Flow High-Pressure Homogenization of Blueberry Juice Enhances Anthocyanin and Ascorbic Acid Stability during Cold Storage.

Blueberries (Vaccinium section Cyanococcus) have a wealth of bioactive compounds, including anthocyanins and other antioxidants, that offer significant health benefits. Preserving these compounds and maintaining the sensory and nutritional qualities of blueberry products such as juice during cold market storage is critical to meet consumer expectations for nutritious, safe, and minimally processed food. In this study, we compared the effects of two preservation processing techniques, high-temperature short-time (HTST) and continuous flow high-pressure homogenization (CFHPH), on blueberry juice quality during storage at 4 °C. Our findings revealed that inlet temperature (Tin) of CFHPH processing at 4 °C favored anthocyanin retention, whereas Tin at 22 °C favored ascorbic acid retention. After 45 days of storage, CFHPH (300 MPa, 1.5 L/min, 4 °C) juice retained up to 54% more anthocyanins compared to control at 0 day. In contrast, HTST treatment (95 °C, 15 s) initially increased anthocyanin concentrations but led to their subsequent degradation over time, while also significantly degrading ascorbic acid. Furthermore, CFHPH (300 MPa, 4 °C) juice had significantly lower polyphenol oxidase activity (>80% less than control), contributing to the overall quality of the juice. This innovative processing technique has the potential to improve commercial blueberry juice, and help meet the rising demand for healthy and appealing food choices.

Effects of High Temperature Short Time and High Hydrostatic Pressure Treatment on the Microbial and Physicochemical Characteristics of Red Beet Juice

Effects of High Temperature Short Time and High Hydrostatic Pressure Treatment on the Microbial and Physicochemical Characteristics of Red Beet Juice

Microstructure and properties of high strength and high conductivity Cu-0.48Cr-0.20Nb-0.27Zn alloy treated by a new combined thermo-mechanical treatment

A Cu-0.48Cr-0.20Nb-0.27Zn (wt.%) alloy with excellent comprehensive performance is designed and prepared by adding Zn element and combining it with a novel combined thermo-mechanical treatment. A high-temperature short-time treatment is introduced to the traditional thermo-mechanical treatment. Results show that the hardness, tensile strength, yield strength, elongation, and electrical conductivity of Cu-Cr-Nb-Zn alloy reach 180HV, 580 MPa, 535 MPa, 7.6%, and 80.2%IACS, respectively. Compared with conventional thermo-mechanical treatment, the alloy after the new process has increased by 15HV, 35 MPa, 40 MPa, 1.3%, and 2.0%IACS, respectively. Submicron grains and nanoscale twins emerge following high-temperature short-time treatment (850 °C/5min), and the grains undergo substantial refinement. Besides, this process promotes the precipitation of solid solution Cr atoms, thereby significantly improving the electrical conductivity of the alloy. Two distinct crystal structures (C14 and C15) of Cr2Nb with diameters ranging from 80 to 200 nm are observed. The alloy's strength is greatly increased in the following aging process, which precipitates a significant quantity of nanoscale Cr phase. All of the above results have certain reference significance for the optimization design of Cu-Cr-Nb alloy composition as well as performance improvement.

Analysis of the Responses to Pasteurization Temperatures of Methicillin Resistant Staphylococcus aureus Derived from Milk Items

Background and Aim: One of the leading causes of both community- and hospital-acquired infections is the superbug," multidrug-resistant Staphylococcus aureus (MRSA). Milk and dairy products seem to be highly vulnerable to a wide range of diseases. Therefore, we require processing procedures that both eliminate pathogens and lengthen the useful life of these products. The purpose of this study was to determine how susceptible MRSA isolates were to pasteurization temperatures after being recovered from dairy products.&#x0D; Materials and Methods: For the purpose of pasteurization, ten MRSA isolates were exposed to both a 63°C LTLT (low temperature, long time) therapy for 30 minutes and a 72°C HTST (high temperature, short time) treatment for 16 seconds.&#x0D; Results: The findings indicated that all isolates were killed by a pasteurization-like treatment at low temperature for a long time (63°C for 30 minutes), but that particular adaptable isolates could survive a pasteurization-like treatment at high temperature for a short time (72°C for 16 seconds), which may point to a time- and temperature-dependent variation in the thermal tolerance mechanism.&#x0D; Conclusion: The results showed that all isolates seemed extremely susceptible to damage from heat using LTLT pasteurization-like treatment (63°C for 30 minutes). Nevertheless, a particular number of these isolates succeeded in establishing colonies because they have quorum sensing structures that survive being handled by using heat damage at 72°C for 16 seconds. Pasteurized milk producers should be alerted to the fact that this microorganism has been found in contaminated milk since it compromises the product's safety and diminishes its value to consumers. As a result, it is strongly advised that manufacturers utilize varied temperatures for milk processing in order to remove the contaminating methicillin- and heat-resistant S. aureus (MHRSA).

Physicochemical properties of fluid milk with different heat treatments and HS-GC-IMS identification of volatile organic compounds

To improve understanding of the effects of industrial heating processes on its physiochemical and flavour properties, fluid milk was evaluated for protein denaturation and flavour volatiles after high-temperature short-time (HTST), indirect ultra-high temperature (IND-UHT) and direct ultra-high temperature with direct steam infusion (INF-dUHT) treatments. Protein denaturation was evaluated by particle size, free sulphydryl content, fluorescence spectra, native whey protein retention rate and microstructure. Volatile organic compounds (VOCs) were compared by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). HTST treatment exerted the lowest negative effect on the aggregation and denaturation of native whey proteins including α-lactalbumin, β-lactoglobulin and lactoferrin, followed by INF-dUHT. IND-UHT caused the most severe denaturation of native whey proteins. HTST-treated milk was characterised by a high level of low molecular weight ketones and INF-dUHT milk possessed the greatest abundance of aldehydes, whereas IND-UHT milk exhibited the highest contents of high molecular weight methyl ketones, which contributed to an unpleasant aroma.

Improving curcumin retention in oil-in-water emulsions coated by chitosan and their disperse stability exposed to thermal treatments

Curcumin-loaded (6% medium-chain triglyceride oil in water) emulsions were coated with chitosan and then treated with different thermal processes, including LTLT (low-temperature, long-time), HTST (high-temperature, short-time), and autoclave treatments. The mean size and zeta-potential of the emulsions linearly increased with increasing chitosan concentrations. All emulsions maintained their initial mean size after LTLT and HTST, but autoclaving increased the emulsion sizes. The size increment diminished with increasing chitosan concentrations. Moreover, 26.1% of the curcumin in non-coated emulsions was degraded during the autoclaving, whereas 83.1% of the curcumin was retained in emulsions coated with 1.0% chitosan. Thus, the emulsions coated with 1% chitosan are applicable to various thermal processing including LTLT, HTST, and autoclaving. All emulsions showed Newtonian fluid behavior, but viscosity increased with increasing chitosan concentrations. Therefore, the emulsion coated with a high chitosan concentration (more than 0.5%) showed enhanced storage stability in turbidimetric analysis despite its high polydispersity index. • Curcumin loaded emulsions were coated with different concentrations of chitosan. • Curcumin retention in emulsions was determined after thermal processing. • Chitosan coating protected the curcumin encapsulated in emulsions against heat. • Chitosan coated emulsions exhibited Newtonian fluid behavior. • Chitosan coating prevented creaming formation of emulsions by destabilization.

Denaturation kinetics and storage stability of Osteopontin in reconstituted infant milk formula

Osteopontin (OPN) is a multifunctional whey protein with numerous health benefits and is recommended to supplement Infant Milk Formula (IMF) with it. For the first time, the denaturation kinetics and storage stability of bovine OPN were studied in reconstituted IMF. The effect of thermal treatments (63–90 °C) and High Pressure Processing (HPP) were investigated. OPN showed higher retention (around 90%) after both LTLT (Low Temperature Long Time) and HTST (High Temperature Short Time) treatments, however higher temperature and longer treatment induced substantial denaturation indicating UHT may not suit OPN-added items. Significant denaturation occurred at higher pressure (>400 MPa), and more pronounced OPN denaturation was observed after HPP at elevated temperature. OPN remained stable during4 °Cstorage for 14 days. This investigation deduced thermal stability of OPN as α-Lac > OPN > LF, whereas the pressure resistance observed as α-Lac > LF > OPN > β-Lg.

A comparative study of the cloudy apple juice sterilized by high-temperature short-time or high hydrostatic pressure processing: shelf-life, phytochemical and microbial view

Cloudy apple juice (CAJ) is popular due to its potential health benefits and pleasant flavor. However, the common used sterilization methods of CAJ by High hydrostatic pressure (HHP) or high-temperature short time (HTST) still showed many inadequacies. The present work studied the impact of HHP (400MPa/10 °C/10 min) and HTST (98 °C/50s) on CAJs made from a new cultivar Changfu 2 planted in Loess plateau area. We comparatively evaluated the microbes inactivation, enzymatic activity, phytochemical parameters, and sensory quality after the HHP and HTST treatment and during the cold storage (4 °C). Results showed that during the cold storage, both HHP and HTST treated CAJ showed a declining trend in sensory attributes like aroma, taste and overall acceptability. HTST showed a higher killing rate of bacteria, and the CAJ was detected a higher diversity of microorganisms (expressed as OTU) during the cold storage. At the end of shelf-life, Rickettsia, oxyphotobacteria, and pseudomonas were detected as the dominant genera in both HHP and HTST treated CAJs. Spearman bivariate correlate analysis determined the relationship between the bacterial profiles and enzymatic activity, phytochemical parameters, and sensory quality after the HHP and HTST treatment.

Preparation and characterization of β‐carotene nanoemulsions stabilized by complexes of tartary buckwheat bran protein and rutin

Tartary buckwheat bran (TBB), which is rich in proteins, is the main waste of tartary buckwheat processing. To improve the value of TBB, the noncovalent and covalent Tartary buckwheat bran protein (TBBP)/rutin complexes were prepared, and their capacities to fabricate β-carotene nanoemulsions were compared. The results indicated that the covalent complex exhibited the highest emulsifying performance, and the corresponding nanoemulsion had the lowest droplet size and polymer dispersity index (PDI) and the highest absolute value of ζ-potential, which could remain stable for four weeks. The high–temperature–short–time treatment and freeze–thaw processing had little influence on this nanoemulsion. However, it was very sensitive to high salt concentrations. Compared with the nanoemulsion prepared by the noncovalent complex, it had higher protein and rutin concentrations at the oil-water interface, which explained the improved stability of β-carotene against high temperature and UV irradiation. Practical applications In this study, the fabrication and characterization of β-carotene nanoemulsion stabilized by the complexes of tartary buckwheat bran protein and rutin are introduced. It can provide a reference for the utilization of other low-value cereal proteins and prompt the development of nutraceutical delivery systems based on food-derived protein-polyphenol complexes.

Revisiting mouse minute virusinactivation by high temperature short time treatment.

In recent years, high temperature short time (HTST) treatment technology has been increasingly adopted for medium treatment to mitigate the potential risk of viral contamination in mammalian cell culture GMP manufacturing facilities. Mouse minute virus (MMV), also called minute virus of mice (MVM), implicated in multiple viral contamination events is commonly used as a relevant model virus to assess the effectiveness of HTST treatment of cell culture media. However, results from different studies vary broadly in inactivation kinetics as well as log reduction factors (LRFs) achieved under given treatment conditions. To determine whether the reported discrepancies stemmed from differences in MMV strains, laboratory-scale HTST devices, medium matrices, and/or experimental designs, we have taken a collaborative approach to systematically assess the effectiveness of HTST treatment for MMV inactivation. This effort was conceptualized based on a media treatment gap analysis conducted by the Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) under the MIT Center for Biomedical Innovation (CBI). Specifically, two different MMV strains were used to evaluate the effectiveness of HTST at various treatment conditions with regard to exposure temperature and hold time duration by two independent laboratories within two different companies. To minimize experimental variations, the two sites used the same batches of MMV stocks, the same commercially purchased medium, and the same model of thermocyclers as the laboratory-scale HTST device. The two independent laboratories yielded similar MMV inactivation kinetics and comparable LRF. No significant differences were observed between the two MMV strains evaluated, suggesting that the variations from prior studies were likely due to differences in equipment, medium matrices, or other factors. The data presented here indicate that MMV inactivation by HTST treatment obeys first-order kinetics and can be mathematically modeled using an Arrhenius equation. The model-based extrapolation provides a quantitative estimate of MMV inactivation by the current industry standard HTST condition (102°C for a hold time of 10 s) used for medium treatment. Finally, based on the data from the current study and the industry experience, it is recommended that any alternative virus barrier technologies adopted for medium treatment should provide a clearance of at least 3.0 LRF based on a worst-case model virus to effectively mitigate potential risks of viral contamination.

Comparative assessment of HTST, hydrodynamic cavitation and ultrasonication on physico-chemical properties, microstructure, microbial and enzyme inactivation of raw milk

The effects of high-temperature short time (HTST), ultrasonication (US) and hydrodynamic cavitation (HC) on physicochemical properties, alkaline phosphatase (ALP) activity, microorganism, degree of protein hydrolysis (DPH), color, microstructure and overall particle size of raw milk were studied. The separation index (SI) was also measured during storage of treated milk at 4 ± 2 °C for 12 days. US was carried out at different intensities (200, 300, and 400 W) and time (4, 6, and 8 min) and HC at 4, 6, 8, and 10 psi for 5, 10 and 15 min. It was observed that HC showed 21% energy efficiency (η) with higher cavitational yield than US which had η <10%. Microbial log reduction of 2.30 ± 0.17 TPC and 2.26 ± 0.17 (YM) was obtained by HTST treatment. And about 0.9 and 0.7 microbial log reduction were observed in HC and US treatment respectively. Initially in non-thermal treatment, ALP activity increases slightly by 1–2% at 4 psi (HC) and 200 W (US), but with further increase in time and intensity, ALP activity decreases. In addition to that, there was an increase in the DPH from 0.716 ± 0.09% to about 3.608 ± 0.52 and 3.77 ± 0.15% in US and HC treated samples respectively. Also, with an increase in time and intensity, number of fat globules increased with a decreased diameter and overall particle size. In non-thermal treatment, except for samples treated at 200 W (US) and 4 psi (HC), no separation was observed during the storage which could be due to reduced size of fat globules (from 6.3 μm to 3–2.2 μm).

High-Temperature Short-Time and Holder Pasteurization of Donor Milk: Impact on Milk Composition.

Holder pasteurization (HoP; 62.5 °C, 30 min) is commonly used to ensure the microbiological safety of donor human milk (DHM) but diminishes its nutritional properties. A high-temperature short-time (HTST) system was designed as an alternative for human milk banks. The objective of this study was to evaluate the effect of this HTST system on different nutrients and the bile salt stimulated lipase (BSSL) activity of DHM. DHM was processed in the HTST system and by standard HoP. Macronutrients were measured with a mid-infrared analyzer. Lactose, glucose, myo-inositol, vitamins and lipids were assayed using chromatographic techniques. BSSL activity was determined using a kit. The duration of HTST treatment had a greater influence on the nutrient composition of DHM than did the tested temperature. The lactose concentration and the percentage of phospholipids and PUFAs were higher in HTST-treated than in raw DHM, while the fat concentration and the percentage of monoacylglycerides and SFAs were lower. Other nutrients did not change after HTST processing. The retained BSSL activity was higher after short HTST treatment than that following HoP. Overall, HTST treatment resulted in better preservation of the nutritional quality of DHM than HoP because relevant thermosensitive components (phospholipids, PUFAs, and BSSL) were less affected.

Physical and turbidimetric properties of cholecalciferol- and menaquinone-loaded lipid nanocarriers emulsified with polysorbate 80 and soy lecithin

The present study aimed to investigate the physical and turbidimetric properties of cholecalciferol- and menaquinone-loaded lipid nanocarriers emulsified with different ratios of polysorbate 80 and soy lecithin. The lipid nanocarriers were subjected to three different heat treatments, LTLT (low temperature long time), HTST (high temperature short time), and autoclave treatments. Both cholecalciferol and menaquinone were successfully encapsulated in lipid nanocarriers and there was little loss of them during preparation. The droplet size of lipid nanocarriers emulsified with only polysorbate 80 increased and its PDI became larger than 0.3 after autoclave treatment. Moreover, 30.9% and 49.4% of cholecalciferol and menaquinone, respectively, were lost. In turbidimetric analysis, the destabilization by creaming formation in the upper layer of the lipid nanocarriers emulsified with a high polysorbate ratio was observed. However, the use of combination of both emulsifiers inhibited destabilization by flocculation as well as retained the cholecalciferol and menaquinone after all heat treatments.

Review: High temperature short time treatment of cell culture media and feed solutions to mitigate adventitious viral contamination in the biopharmaceutical industry.

Events of viral contaminations occurring during the production of biopharmaceuticals have been publicly reported by the biopharmaceutical industry. Upstream raw materials were often identified as the potential source of contamination. Viral contamination risk can be mitigated by inactivating or eliminating potential viruses of cell culture media and feed solutions. Different methods can be used alone or in combination on raw materials, cell culture media, or feed solutions such as viral inactivation technologies consisting mainly of high temperature short time, ultraviolet irradiation, and gamma radiation technologies or such as viral removal technology for instance nanofiltration. The aim of this review is to present the principle, the advantages, and the challenges of high temperature short time (HTST) technology. Here, we reviewed effectiveness of HTST treatment and its impact on media (filterability of media, degradation of components), on process performance (cell growth, cell metabolism, productivity), and product quality based on knowledge shared in the literature.

Effect of Heat Treatment on Rheological Properties of Bambangan (Mangifera pajang kosterm) Fruit Juice

Bambangan (Mangifera pajang Kosterm) is an indigenous fruit that can be found in Borneo Island including Sabah and Sarawak (Malaysia), Kalimantan (Indonesia), and Brunei. Besides being freshly eaten, the pulp of bambangan fruit can be processed for juice production to expand its market potential. During the processing of fruit juice, the application of heat treatment such as pasteurization and sterilization might influence their rheological behavior. Thus, the present study aims to investigate the effect of heat treatment on the rheological properties of bambangan fruit juice (BFJ). The freshly squeezed BFJ was subjected to different heat treatment conditions; sterilization (121°C, 3 minutes), mild temperature long time (MTLT) pasteurization (65°C, 15 minutes), and high temperature short time (HTST) pasteurization (90°C, 1 minute). Rheological analysis of the heat-treated BFJ was performed using a rheometer at a shear rate ranging from 1 to 250 s-1 and a temperature between 5 °C to 70 °C. Pasteurization at 90 °C for 1 minute (HTST) was found to be the most suitable heat treatment for the BFJ. At this condition, the BFJ exhibited a non-Newtonian pseudoplastic fluid behavior (n &lt; 1), fitted well with the Herschel-Bulkey model. The value of parameters obtained from Herschel-Bulkley equation for HTST treatment of bambangan juice were n= 0.83, k= 0.32 and yield stress= 3.96. The viscosity values of HTST bambangan juice at the temperature of 5, 20, 40 and 70 °C were 3.53, 2.33, 1.53 and 1.76 Pa.s respectively. This rheological information is of fundamental importance in optimizing equipment design, process control, and sensory evaluation.

Molecular mobility changes after high-temperature, short-time pasteurization: An extended time-domain nuclear magnetic resonance screening of ewe milk

This study presents an extensive investigation on the effect of pasteurization on raw whole ewe milk. Milk samples have been analyzed, throughout lactation (from February to July), by time-domain nuclear magnetic resonance (TD-NMR), collecting the characteristic TD-NMR relaxation parameters, proton longitudinal and transverse relaxation times (1H T1 and T2). Collected data aim at integrating previous NMR works, mainly focusing on dairy model systems (casein and whey proteins solutions and gels, reconstituted skim milk) and cheese, with specific reference to the effect of heat treatments. Whole ewe milk, from a single flock (Sarda sheep breed), was daily analyzed both as untreated (raw) and heat treated with a laboratory-scaled high-temperature, short-time treatment (72°C for 15 and 20 s). Moreover, molecular dynamics in milk were investigated by TD-NMR in different periods of lactation for the first time. As a consequence of high-temperature short-time treatment, 1H T1 and T2 consistently shifted to lower values with respect to raw counterparts. Statistical analysis indicated a significant decrease of T2 in treated samples, to an extent dependent on the heat treatment duration. A subset of dedicated experiments demonstrated that the observed T2 shift is largely ascribable to protein molecular rearrangements and, to a lesser extent, to the interaction of fat globules with proteins or other nonfat components (or both). In light of the crucial importance of detecting the application of a heat treatment to milk, the results reported here suggest TD-NMR relaxation parameters were able to describe heat-induced changes in molecular dynamics and interactions of milk components in a water-rich environment. The use of TD-NMR can be considered a potential suitable technique for quality control and assurance practices in the dairy industry. Upon statistical validation of methods, the application of TD-NMR in the dairy industry would take advantage of its low cost, reliability, and robustness.

Sugarcane juice pasteurization: A search for the most effective parameters

This study targeted the optimization of holding time and temperature for sugarcane juice pasteurization. The temperature, ranging from 78 to 92°C, and holding time, from 16 to 44 s, were tested. The responses of different combinations were evaluated by microbiological, enzymatic, sensory assays, and instrumental measurement of color. The impact of the binomials widely varied. With respect to enzymatic inactivation and microorganisms reduction, the treatment at 90°C/40 s was the most efficient. The binomial 85°C/44 s was more effective in maintaining the original juice color. As to the sensory quality, the treatment at 85°C/16 s had a better performance compared to the others. The findings of this study demonstrated that there is not one unique binomial able to meet all requisites needed for cane juice stabilization. The data hereby presented may be useful to design a high temperature short time (HTST) treatment for a “clean label” whole juice. Practical applications Much effort has been put forth to optimize cane juice stabilization, and pasteurization can be successful through well designed heat treatment processes. This study demonstrates there is not a unique time x temperature binomial that provides for all requisites of cane juice stabilization. Given this, the data herein may provide useful design guidelines for industrial scale thermal processing of whole juice.

Exploring optimal strategies for aquatic macrophyte pre-treatment: Sustainable feedstock for biohydrogen production

Aquatic macrophytes; Water hyacinth (Eichhornia crassipes) and Azolla, biomass have certain advantages over terrestrial plant biomass to use as non-edible feed for 2nd generation bioenergy production. This is mainly due to the lower lignin content and higher productivity of aquatic macrophytes. These macrophytes do not require arable land. Present study explored on development of factorial approach based optimal pretreatment process for mild acid hydrolysis of Eichhornia crassipes and Azolla microphylla biomass for conversion to fermentable sugars. The simpler structure of aquatic plants translates to higher sugar recovery using milder pretreatment conditions compared to terrestrial plants. H2SO4 & HCl used in mild concentrations for acid hydrolysis experiments. Approximately, 20% of the dry biomass was recovered as fermentable sugar (mainly xylose) upon treatment with dilute sulphuric acid (0.5–1.5% v/v) or hydrochloric acid (2–4% v/v) at 100–120 °C for 30–60 min. Within this range of parameters, sugar yield followed a simple additive model, implying that a decrease in sugar yield is due to reduction of one parameter. This provides a choice between high temperature short time (HTST) and low temperature long time (LTLT) treatments. HTST requires sophisticated pressure vessels and correspondingly higher capital investment for the advantage of a higher throughput. LTLT treatments can be performed in cost economy manner using relatively simple equipment. For economic, environmental and technical reasons, acid addition should be kept to a minimum, which is possible by a choice of higher temperature and longer treatment time. Such pretreatment may be employed as the first step of a two-step pretreatment process prior to enzymatic saccharification of cellulosic fraction. The acid pre-treated hydrolysate of water hyacinth and Azolla microphylla explored for hydrogen production through dark fermentation process through employment of C5 & C6 sugar utilizing microbe Enterobacter cloacae DT-1 strain.

Time-temperature-resolved functional and structural changes of phycocyanin extracted from Arthrospira platensis/Spirulina

Arthrospira platensis, commonly known as Spirulina, gains increasing importance as alternative protein source for food production and biotechnological systems. A promising area is functional high-value algae extracts, rich in phycocyanin, a protein-pigment complex derived from A. platensis. This complex has proven functionality as the only natural blue colorant, fluorescent marker and therapeutic agent. The structure-function relationship is heat sensitive, making thermal processing in its production and its subsequent application a crucial aspect. In continuous high-temperature short-time treatments, it was shown how a purified phycocyanin (mixture of allophycocyanin and c-phycocyanin) disassembled and denatured between 50 and 70 °C. Three characteristic transition temperatures were allocated to specific quaternary aggregates. In contrast to sequential chemical denaturation, phycocyanin’s chromophore and protein structure were simultaneously affected by thermal processing. Through a functionality assessment, the findings help optimize the efficiency of raw material usage by defining a processing window, enabling targeted process control resulting in desired product properties.