Üç farklı infüzyon tekniğiyle elde edilen hibiskus (Hibiscus sabdariffa L.) çaylarının aroma ve aroma-aktif bileşiklerinin karakterizasyonu.

TEZ12427Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2017.Kaynakça (s. 71-93) var.XVII, 95 s. :_rnk. res., tablo ;_29 cm.Bu çalışmada, Hibiscus sabdariffa çayının aroma, aroma-aktif maddeleri, toplam fenolik içeriği ve antioksidan aktivitesi üzerine Benin’de sıklıkla kullanılan iki farklı geleneksel demleme yönteminin (TI1 (40 dakika/100°C) ve TI2 (24 saat/oda koşullarında)) ve literatürde Ramirez-Rodrigues ve ark. (2011) tarafından önerilen alternatif bir çay demleme yönteminin (IR (16 dakika/98°C)) etkisi incelenmiştir. Örneklerin aroma maddelerinin belirlenmesinde sıvı-sıvı ekstraksiyon metodu kullanılmıştır. Çaylarda aroma-aktif bileşikler, Aroma Ekstrakt Seyreltme Analizi (AESA) uygulanarak GC-MS-Olfaktometri tekniği ile araştırılmıştır. TI1, TI2 ve IR örneklerinde GC-MS yardımıyla sırasıyla 38, 39 ve 38 adet aroma bileşiği tespit edilmiştir. Oda koşullarında 24 saat ile hazırlanan çay örneklerinin aroma maddeleri miktarı açısından en zengin olduğu saptanmıştır (176545 ?g/kg). Örneklerdeki aroma bileşiklerinin büyük bir kısmını furan bileşiklerinin oluşturduğu ve bu grupta furfural bileşiğinin yüksek miktarda bulunduğu belirlenmiştir. Aroma-aktif bileşikleri bakımından furfural (karamel) tüm örneklerde en baskın aroma-aktif bileşik olarak belirlenmiştir (SF=2048- 4096). Diğer güçlü aroma-aktif bileşikleri ise, 5-metil-2-furfural (karamel), asetik asit (sirke kokusu), 3-penten-2-ol (yağımsı, bitki), nonanal (bitki, çimenli), benzaldehit (badem), öjenol (baharat) ve 3-metil-3-büten-2-on (meyvemsi) olarak belirlenmiştir. Aroma-aktif bileşiklerinin seyreltme faktörü TI2 çay örneğinde daha yüksek çıkmıştır. Duyusal analize gelince, GC-MS-O sonuçları ile paralel olarak, TI2 infüzyonu panelistler tarafından daha çok tercih edilmiştir. Örneklerin toplam fenolik içeriği Folin-Ciocalteu yöntemi ile belirlenmiş ve TI1, TI2 ve IR’nin toplam fenolik içeriği sırasıyla 2135; 1556 ve 2201 mg/L gallik asit eşdeğeri olarak saptanmıştır. Hibiskus çayı örneklerinin antioksidan aktivitesi ise DPPH yöntemi kullanılarak belirlenmiştir. TI1, TI2 ve IR’in toplam antioksidan aktivitesi sırasıyla 714, 358 ve 761 mM Trolox eşdeğeri/kg olarak belirlenmiştir. Bu çalışma, çay hazırlama yöntemlerinin Hibiscus sabdariffa'nın toplam fenolik bileşikleri, antioksidan aktivitesi, aroma ve aroma-aktif profilini önemli ölçüde etkileyebileceğini göstermiştir. Çay örneklerinden, TI2 (24 saat/oda koşullarında) infüzyonunun aroma ve aroma-aktif bileşikleri açısından daha zengin olduğu ve duyusal açısından da diğer örneklere göre daha çok tercih edildiği belirlenmiştir.In this study, the effects of two different traditional brewing methods used frequently in Benin (TI1 (40 minutes/100°C) and TI2 (24 hours/ ambient temperature)) and an alternative brewing method suggested by Ramirez-Rodrigues et al. (2011) (IR (16 minutes/ 98 °C)) on aroma, aroma-active compounds, total phenolic content and antioxidant activity of Hibiscus sabdariffa tea were investigated. Liquid-liquid extraction method was used to determine the aroma of the samples. The aroma-active compounds were investigated by GC-MSOlfactometry technique by applying Aroma Extract Dilution Analysis (AEDA). A total of 38, 39 and 38 aroma compounds were identified by GC-MS in TI1, TI2 and IR, respectively. The highest amount of aroma compounds was found in TI2 sample (176545 ?g/kg). Furans were the most dominant volatiles in Hibiscus sabdariffa teas with the lead of furfural in general. Furfural was identified as the most dominant aroma-active compound (FD=2048-4096) responsible for caramel, bready odors in all samples. Another aroma-active compounds detected in roselle infusions with high intensities were 5-methyl-2-furfural (caramel), acetic acid (vinegary), 3-penten-2-ol (oily, herbal), nonanal (herbal, grassy), benzaldehyde (almond), eugenol (spicy) and 3-methyl-3-buten-2-one (fruity). The FD factors of these Hibiscus sabdariffa aroma-active compounds were relatively higher in TI2. Sensory evaluation revealed that TI2 is more preferred by panellists and displayed higher intensities of aroma, fruity, sweet and caramel attributes than TI1 and IR. This is in agreement with results from the olfactometric analysis. The total phenolic contents of TI1, TI2 and IR determined by Folin-Ciocalteu method were 714, 358 and 761 mg/kg gallic acid equivalents, respectively. Antioxidant activity of TI1, TI2 and IR investigated with DPPH assay were 714, 358 and 761 mM/kg Ttrolox equivalents respectively. This study has shown that sample preparation methods can significantly affect the total phenolic compounds, antioxidant activities, aroma and aroma-active profiles of Hibiscus sabdariffa. When compared to the tea samples, TI2 (24 hours/ ambient temperature) tea was determined to be richer in aroma and aroma-active compounds and this infusion had greater sensory acceptability than other teas (TI1 and IR).Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: FYL-2017-8664

Impact of Soil Fertility Management Methods on Cereal Production: Case of African and Asian Countries

International audienceThe issue of soil fertility management is increasingly being addressed at various scientific symposia and symposia. This recurrence is explained by the fact that land is the primary factor of production in agriculture and that it is important to preserve it. This study is part of the evaluation of the impact of soil fertility management methods on cereal production in the African and Asian continents. For this purpose, this study was based on the existing literature on the topic. Scientific documents have been obtained from various libraries and research sites. The analysis of the information collected shows that soil fertility management methods vary very little from one continent to another. In general, grain producers from both the African and Asian continents are opting for a change in the technical production routes, the association of livestock with agriculture, and the promotion of organic production. One of the management styles of African producers is fallow. These management methods have a negative as well as a positive impact on cereal production. Like other modes, organic production induces low yields and requires the producer a large work force. At the same time, the crop products obtained can be stored longer without any decomposition. It is therefore imperative to identify new management approaches or to develop the management methods used by producers in order to reduce the negative impact of these modes on cereal production

Extraction of Anthocyanins from Borage (<i>Echium amoenum</i>) Flowers Using Choline Chloride and a Glycerol-Based, Deep Eutectic Solvent: Optimization, Antioxidant Activity, and In Vitro Bioavailability

Borage flower (Echium amoenum), an annual herb native to the Mediterranean region, is an excellent source of anthocyanins and is widely used in various forms due to its biological activities. In the present study, a choline chloride and glycerol (CHGLY)-based natural deep eutectic solvent (NADES) was applied in order to extract the anthocyanins from borage flowers. The traditional solvents, including water, methanol, and ethanol, were used to evaluate the efficiency of CHGLY. The results showed that CHGLY was highly efficient compared to the traditional solvents, providing the highest amounts of the total anthocyanin content (TAC), total phenolic content (TPC), total flavonoid content (TFC), individual anthocyanins, and antioxidant activity (DPPH radical scavenging (DPPH) and ferric-reducing antioxidant power (FRAP) assays). The most dominant anthocyanin found in studied borage was cyanidin-3-glucoside, followed by cyanin chloride, cyanidin-3-rutinoside, and pelargonidin-3-glucoside. The bioavailability % was 71.86 ± 0.47%, 77.29 ± 0.57%, 80.22 ± 0.65%, and 90.95 ± 1.01% for cyanidin-3-glucoside, cyanidin-3-rutinoside, by pelargonidin-3-glucoside and cyanin chloride, respectively. However, cyanidin-3-glucoside was the anthocyanin compound showing the highest stability (99.11 ± 1.66%) in the gastrointestinal environment. These results suggested that choline chloride and glycerol-based NADES is not only an efficient, eco-friendly solvent for the extraction of anthocyanins but can also be used to increase the bioavailability of anthocyanins

Recovery and Stabilization of Anthocyanins and Phenolic Antioxidants of Roselle (Hibiscus sabdariffa L.) with Hydrophilic Deep Eutectic Solvents

Deep eutectic solvents (DESs) have got huge interest as new green and sustainable solvents for the extraction of bioactive compounds from plants in recent decades. In the present study, we aimed to investigate the effectiveness of hydrophilic DES for the extraction of anthocyanin and polyphenol antioxidants from Roselle. A natural hydrophilic DES constituted of sodium acetate (hydrogen bond acceptor) and formic acid (hydrogen bond donor) designed to evaluate the total phenolic compound (TPC), total flavonoid (TFC), total anthocyanin (TACN), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) values of Roselle. Distilled water, 70% ethanol, and 80% methanol used as conventional solvents for comparison. The results indicated that the DES prepared in molarity ratio (SAFAm) was the most efficient. Subsequently, this prominent DES selected for the optimization and the optimum extraction conditions were 1:3.6 molarity ratio, 0% additional water, and 10 mL solvent. TPC, TFC, TACN, FRAP, and DPPH radical scavenging at the optimum point were 233.26 mg GAE/g, 10.14 mg ECE/g, 10.62 mg D3S/g, 493.45 mmol ISE/g, and 343.41 mmol TE/g, respectively. The stability tests showed that anthocyanins were more stable in SAFAm. These findings revealed that SAFAm is an effective green solvent for the extraction of polyphenols from various plants

Corn production and processing into ethanol in Turkey: An analysis of the performance of irrigation systems at different altitudes on energy use and production costs

This research aims to assess the energy input and output involved in corn production in the Elazig province of Turkey in different agricultural systems. This study is interested in energy resource allocation to analyze maize production systems since the value of production inputs and outputs is affected by economic crises as well as the country's politico-economic status. The amounts of energy used for production are still very challenging to change. The typical energy usage of the farms examined in this study is 3359,82 MJda−1, 3715,74 MJda−1, 5366,13 MJda−1 and 6456,24 MJda−1 according to the distance between the water sources and the farms. Of the total mean of energy, 31.06% is direct, 12, 26% is indirect, 14,38% in renewable energy and 42,30% in non-renewable energy. A kilogram of typical maize is thought to require 3,93 MJ of energy in total to produce. Energy used for irrigation makes up most of the input (37.20%), followed by sowing (22.57%) and fertilizer (16.65%). As a result of the benefit-cost ratio analysis is 0.29, the cost of corn production per decare is found to be $112.05/da in the area, with variable costs accounting for 83.17% of the total. The analysis of data reveals that the transformation of 100 kg of corn generates an energy expenditure of 2219.58 MJ and more than 50% of energy expenditure comes from the use of machines

Vacuum-Assisted Osmotic Dehydration of Autumn Olive Berries: Modeling of Mass Transfer Kinetics and Quality Assessment

Autumn olive fruits were osmo-dehydrated in sucrose solution at 70 °C under vacuum and atmospheric pressure. The mass transfer kinetics data were applied to the models of Azuara, Crank, Page, and Peleg. The Peleg model was the best-fitted model to predict the water loss and solid gain of both treatments. The vacuum application decreased the effective diffusivities from 2.19 × 10−10 to 1.55 × 10−10 m2·s−1 for water loss and from 0.72 × 10−10 to 0.62 × 10−10 m2·s−1 for sugar gain. During the osmotic dehydration processes, the water activity decreased and stabilized after 5 h, while the bulk densities increased from 1.04 × 103 to 1.26 × 103 kg/m3. Titratable acidity gradually reduced from 1.14 to 0.31% in the atmospheric pressure system and from 1.14 to 0.51% in the vacuum system. pH increased significantly in both systems. Good retention of lycopene was observed even after 10 h of treatments. For the color parameters, the lightness decreased and stabilized after 30 min. In comparison, the redness and yellowness increased in the first 30 min and gradually decreased towards the initial levels in the fresh fruit

Socio-cultural and economic factors affecting the choice of food diet in West Africa: a two‑stage Heckman approach

International audienceWest African countries have made impressive progress in fighting against malnutrition and hunger and ensuring food quality and varying food choices. This paper aimed for the first time to evaluate the determinants of diet choice by the populations of West Africa, especially those of Benin, Togo, and Nigeria. The data collected from 473 people relate mainly to their socioeconomic and cultural characteristics and the factors determining the choice of the diet for which they have opted. These data were analyzed using the Tobit model based on the Heckman method. The statistical analysis of the results obtained allowed us to deduce that the populations studied generally opt for a flexitarian, vegetarian or vegan diet. The age, level of education, religious and ancestral beliefs, social framework, monthly income, perception of the costs generated by each diet, perception of the consumption of products of animal origin such as meat and fish have a significant influence on the choice of diet. The intensity of the chosen diet was determined by variables such as sex, level of education, social framework, perception of consumption of animal products, and meat and fish. Diet being a determining parameter of our state of health, it is imperative to make people aware of the different diets so that they can identify and adopt the one that suits them best

Tomato pomace as a source of valuable functional ingredients for improving physicochemical and sensory properties and extending the shelf life of foods: A review

Due to its nutritional and bioactive content, tomato pomace (TP) remains among the world's richest fruits and vegetables. Tomatoes and TP (generated coproduct) are a very rich source of lycopene and other carotenoid compounds and contain an essential amount of polyphenols, policosanol, phytosterols, organic acids, dietary fibers, minerals, and vitamins. TP is a promising source of significant bioactive compounds with antioxidant and antimicrobial potential. Therefore, their consumption is known to be effective in preventing certain chronic diseases. For example, lycopene prevents prostate cancer and acts as a hepatoprotector and genoprotector against mycotoxins, pesticide residues, and heavy metals. Thus, the valorization of TP as a food ingredient can be of great health, economic and environmental interest and contribute to improving nutrition and food security. During the last decades, considerable efforts have been made to valorize TP as a crucial functional ingredient in improving: (i) the nutritional and functional properties, (ii) sensory characteristics and (iii) the shelf life of many foods. The current review aims to update and summarize the knowledge on the recent food applications of TP, particularly its use as a functional ingredient to improve the functional properties and shelf life of foods

Optimization of Osmotic Dehydration of Autumn Olive Berries Using Response Surface Methodology

Autumn olive fruits are a rich source of nutrients and functional compounds, making them functional foods against many diseases and cancers. To increase the consumption, its processing, and its transformation into new products would help spread them to the consumer’s table. In this study, after giving an overview of the physicochemical characteristics and the antioxidant activity, the objective was to optimize the osmotic dehydration (OD) of the berries. Response surface methodology was used to investigate the effect of dehydration factors: syrup concentration (30–70%), temperature (20–70 °C), and fruit-to-syrup ratio (1:10–2:10) on the water loss (WL), sugar gain (SG), weight reduction (WR), density (ρ), water activity (aw), and total color change (ΔE) of fruits after 10 h of OD. Results obtained by employing Box–Behnken design (three variables, three levels), and significant terms of regression equations indicated that the syrup concentration and temperature variation are the most affecting factors on the previously mentioned independent variables (WL SG, WR, ρ, aw, and ΔE). Fruits to syrup ratio appeared to have a significant effect only on WL. Under the optimum conditions found (70%, 70 °C, 1.8:10), the predicted values were 59.21%. 19.21%, 32.34%, 1.22 g/cm3, 0.850, and 3.65 for WL, SG, WR, ρ, aw, and ΔE, respectively

Avoiding Food Neophobia and Increasing Consumer Acceptance of New Food Trends&mdash;A Decade of Research

The increasingly fierce competition in food trends requires producers to innovate and develop new foods to be accepted and to avoid neophobia by consumers at the same time. Food neophobia&rsquo;s motivational adoption barriers include the consumption of novel foods, social norms and conflicting eating goals. Therefore, appropriate strategies are needed to avoid neophobia amid the presence of new food trends in the market. Efforts to avoid food neophobia can also be accepted as part of the sustainability concept, in which the consumer has new foods to choose from in order to reduce scarcity in one particular type of food. The food industry is also challenged to produce healthy food by producing food from natural ingredients. In this article, new food trends and advances in food processing are described, and through them, strategies to avoid neophobia and increase consumer acceptance of new food trends are referenced. Neophobia meets marketing food products delivered to consumers facing motivational adoption barriers, such as the consumption of novel foods, social norms and conflicting eating goals, which are indicated to be challenges to purchase drivers in new food trends. Tasting foods is indicated as one of the most efficient means to ensure neophobia reduction in new foods and new food trends. Other factors identified to reduce food neophobia are education, income, taste and exposure to novel foods. Some preconditions for novel foods to be accepted by consumers are related to the very nature of food innovation, the manufacturer&rsquo;s features and market circumstances. Food processed with advanced technologies may differ depending on the brand of the food production company and the knowledge of consumers about the novel foods. Moreover, food technology is seen as more acceptable for plant food products based or natural ingredients for consumers. In addition to the focus on health benefits, it is supports the sustainability of food systems. Another accidental element is the transparent traceability system providing accurate and adequate information about such novel foods