Instant Controlled Pressure-Drop (DIC) for Volatile Compound Extraction and Bioethanol Production from Empty Aleppo Pinecones and Eucalyptus Chips: Process Optimization and Statistical Modeling

Several plant species contain volatile compounds extracted as "essential oils" through different technologies. After essential oil extraction, the residual solid is a lignocellulosic solid waste. This work proposes the instant controlled pressure-drop (DIC) technology to autovaporize volatile compounds and modify the lignocellulosic matrix. Indeed, DIC technology is a thermomechanical process based on short-time/high-temperature and pressure pretreatment. It enhances the saccharification and fermentation process (SSF) for bioethanol production. A 3-variable design of experiments optimized the DIC processing parameters to reach 100% efficiency (EE) of volatile compound extraction using response surface methodology (RSM). Eucalyptus chips presented 50 volatile identified compounds after 7 min of DIC treatment. 1,8-Cineole, β-phellandrene, aromadendrene, eudesmol, and spathulenol are the most important volatile compounds. The empty Aleppo pinecones delivered 32 volatile compounds in 5 min of DIC treatment, the most important of which were caryophyllene, nortricyclene, verbenol, and camphor. After the autovaporization extraction stage, solid fraction residues were hydrolyzed and fermented in the same stirred bioreactor, using SSF strategy for 72 h at 37 °C. The highest bioethanol yields reached 73.9% and 54.82% (g per 100 g DM) from eucalyptus chip and empty Aleppo pinecone, respectively.

Optimization of DIC-Tripolium Ecofriendly Extraction Process: Recovery of Hesperidin from Orange Byproducts, Antioxidant and α-Amylase Inhibition of Extracts

This study aimed to investigate the effect of an innovative ecofriendly process-instant controlled pressure drop technology, also known as "détente instantanée contrôlée" or DIC-coupled with Tripolium extraction (DIC-Tripolium), on the hesperidin recovery, and antioxidant and antidiabetic activities of orange byproduct extracts. A DIC pretreatment was applied to partially dried orange byproducts (~16% wet basis). A central composite rotatable design (CCRD), composed of 13 experimental trials (four factorial points, four-star points, and five repetitions for the central point), was followed by a Tripolium process consisting of successive intermittent extraction periods using ethanol/water solvent at 20 ± 1 °C, 5 kPa for 5 min and m/v ratio = 5 g/50 mL. The DIC pretreatment, coupled with the Tripolium process, increased the extractability of hesperidin (from 1.55- to 4.67-fold compared to untreated DIC orange byproducts). The radical scavenging activities of the extracts were also enhanced or preserved in different DIC-Tripolium extracts. The α-Amylase inhibition percentage varied between 55.6 ± 0.02 and 88.30 ± 0.01% according to DIC-Tripolium conditions. The multi-criteria optimized condition of DIC-Tripolium extraction, allowing for the maximization of the hesperidin content, radical scavenging activities, iron chelating activity, and α-amylase inhibition of extracts, corresponds to a DIC saturated steam pressure of 599.4 kPa and a DIC pretreatment time of 38 s.

Investigation of a mpox outbreak in Central African Republic, 2021-2022

Human monkeypox virus is spreading globally, and more information is required about its epidemiological and clinical disease characteristics in endemic countries. We report the investigation of an outbreak in November 2021 in Central African Republic (CAR). The primary case, a hunter, fell ill after contact with a non-human primate at the frontier between forest and savannah. The ensuing investigation in a small nearby town concerned two families and four waves of inter-human transmission, with 14 confirmed cases, 11 suspected cases and 17 non-infected contacts, and a secondary attack rate of 59.5% (25/42). Complications were observed in 12 of the 19 (63.2%) confirmed and suspected cases with available clinical follow-up data: eight cases of bronchopneumonia, two of severe dehydration, one corneal ulcer, one abscess, two cutaneous superinfections, and six cutaneous sequelae (cheloid scars, or depigmentation). There was one death, giving a case fatality ratio of 1/25 (4.0%) for confirmed and suspected cases. This outbreak, with the largest number of confirmed cases ever described in CAR, confirms the potential severity of the disease associated with clade I monkeypox viruses, and highlights the need for rapid control over virus circulation to prevent the further national and international spread of infection.

Optimisation of Instant Controlled Pressure Drop (DIC)-assisted dehydrofreezing using Response Surface Methodology towards better bioactive compounds retention of quince fruit

Pre-drying prior to freezing may reduce several freezing drawbacks. Nevertheless, drying may cause nutritional quality losses. Instant Controlled Pressure Drop process has been proposed to intensify pre-drying process. This research is dedicated to study the evolution of the main bioactive compounds (total phenolics, flavonoid, and tannins contents) of quince dehydrofrozen fruits. Fresh samples were subjected to air drying at 40 °C and 3 m s−1 air velocity down to a final water content of 0.3 g g−1 db. Pre-dried samples were Instant Controlled Pressure Drop (DIC) treated under different conditions, i.e. saturated steam pressure (P) and treatment time (t), following a 2-factor/5-level Experimental Design. Treated fruits were frozen at –30 °C then were thawed at 20 °C in order to study the impacts of DIC on phenolic compounds. Response Surface Methodology (RSM) confirmed that pressure was the most influencing parameter in terms of polyphenol, flavonoid, and tannins contents. Finally, DIC pre-treatment allowed the improvement of phenolic content retention compared to untreated DIC samples.

Instant Controlled Pressure Drop as Blanching and Texturing Pre-Treatment to Preserve the Antioxidant Compounds of Red Dried Beetroot (Beta vulgaris L.)

Red beetroot is rich in bioactive compounds such as polyphenols, flavonoids, betaxanthins, betacyanins, among others. According to selected processing methods, the bioaccessibility of these compounds could be either enhanced or decreased. This study evaluated the effect of four different drying conditions: (1) Traditional Drying (TD), (2) Swell Drying (SD), (3) DIC Blanching + Traditional Drying (BTD), and (4) DIC Blanching + Swell Drying (BSD) on the antioxidant content and the antioxidant activity of red beetroots. Obtained results showed that in all the cases, by comparing to Traditional Drying (TD), the coupling of a DIC Blanching pre-treatment to a Swell Drying treatment (BSD) maintained or enhanced the preservation of the Total Phenolic Compounds (TPC), the Total Flavonoids Compounds (TFC), the Betanin Concentration (BC), the Trolox Equivalent Antioxidant Capacity (TEAC), and the Free Radical Scavenging Activity by DPPH (IC50) of red beetroots. Various studies have shown that thanks to the expanded and porous structure triggered by the Swell Drying process, it has been possible to achieve better antioxidants extraction and better whole quality. Hence, by coupling DIC as a blanching–steaming pre-treatment, it was possible to preserve better the antioxidant content and the antioxidant activity of red dried beetroots.

Pressure, temperature and processing time in enhancing

Instant Controlled Pressure Drop (DIC) was evaluated as a texturing pre-treatment for the extraction of Camelina sativa (L.) oil. DIC was coupled to Accelerated Solvent Extraction (ASE), Pressing and Dynamic Maceration (DM). DIC optimization was performed by studying the effects of pressure, temperature and processing time on oil yield. DIC + ASE obtained seed-oil yields of 615.9±0.5 against 555.5±0.5 g oil/kg-ddb for untextured seeds (RM). Via pressing, oil yields were 490.9±0.5 and 444.7±0.5 g oil/kg-ddb for textured and untextured seeds, respectively. Through coupling DIC (P: 0.63 MPa and t: 105 s) to the pressing extraction (60 s) of seeds along with 2h of DM of meals, it was possible to reach 605.8 g oil/kg ddb of oil yield. The same results were not obtained for RM seeds, where after 24 h of DM extraction, the oil yield was 554.7 g oil/kg ddb. DIC allowed for an increase in Camelina oil yields, reduced extraction time and valorized pressing meals.

Influence of Instant Controlled Pressure Drop (DIC) on Allergenic Potential of Tree Nuts

Pistachio and cashew contain allergenic proteins, which causes them to be removed from the diet of allergic people. Previous studies have demonstrated that food processing (thermal and non-thermal) can produce structural and/or conformational changes in proteins by altering their allergenic capacity. In this study, the influence of instant controlled pressure drop (DIC) on pistachio and cashew allergenic capacity has been studied. Western blot was carried out using IgG anti-11S and anti-2S and IgE antibodies from sera of patients sensitized to pistachio and cashew. DIC processing causes changes in the electrophoretic pattern, reducing the number and intensity of protein bands, as the pressure and temperature treatment increment, which results in a remarkable decrease in detection of potentially allergenic proteins. The harshest conditions of DIC (7 bar, 120 s) markedly reduce the immunodetection of allergenic proteins, not only by using IgG (anti 11S and anti 2S) but also when IgE sera from sensitized patients were used for Western blots. Such immunodetection is more affected in pistachio than in cashew nuts, but is not completely removed. Therefore, cashew proteins are possibly more resistant than pistachio proteins. According these findings, instant controlled pressure drop (DIC) can be considered a suitable technique in order to obtain hypoallergenic tree nut flour to be used in the food industry.

Apple juice concentrate impregnation enhances nutritional and textural attributes of the instant controlled pressure drop (DIC)-dried carrot chips

BACKGROUND

Osmotic pretreatment is an effective processing unit for improving the textural quality of dried fruit and vegetable snacks, whereas nutrition loss and high calorie after impregnation is still a noteworthy shortcoming of sugar-immersed products. Therefore, the use of apple juice concentrate as a clean label solution to improve the qualities of instant controlled pressure drop (DIC)-dried carrot chips was investigated.

RESULTS

Apple juice concentrate impregnation substantially enhanced the physical properties of the carrot chips, including hardness (38.28 N), crispness (2.01 mm), porosity (66.72%) and homogeneous microstructure, comparable to chips obtained using sucrose and maltiltol based osmotic solutions. Additionally, compared to the sucrose and maltiltol impregnated chips, a higher retention of carotenoids (302.81 μg g^-1 , dry basis), a higher multiplicity of phenolic compounds, stronger antioxidant activities and a superior sensory score were observed in the chips pretreated with apple juice concentrate.

CONCLUSION

Apple juice concentrate could be used as a clean label osmotic solution to enhance the organoleptic attributes and fortify the nutritional properties of DIC-dried carrot snacks. © 2019 Society of Chemical Industry.