53 research outputs found
Assessment of Total Phenolic Compounds, Antioxidant Capacity, β-Carotene Bioaccessibility, HMF Formation, and Color Degradation Kinetics in Pumpkin Pestils
No full textPestil, often known as fruit leather, is one of the most significant traditional foods manufactured and consumed throughout Türkiye. Due to its practical consumption, the availability of numerous nutrients, and the ability to meet energy requirements, pestil is recognized as a snack food. The aim of this study was to evaluate the bioaccessibility of total phenolic compounds (TPC), antioxidant capacity (AOC), and β-carotene in pumpkin pestils dried by hot air drying (HAD), vacuum drying (VCD), and microwave drying (MD) methods using an in vitro digestion model. Additionally, 5-hydroxymethylfurfural (HMF) formation and color degradation of pestils were evaluated. Changes in TPC and AOC were determined using spectrophotometric methods, whereas the detections of β-carotene and HMF were carried out with high performance liquid chromatography–photodiode array detector (HPLC–PDA). Significantly higher TPC (10.99–105.70%) and AOC (15.30–118.58%, 21.88–401.04% and 89.28–482.14%, in CUPRAC, FRAP, and DPPH assays, respectively) values were observed after drying (p<0.05). Moreover, it was observed that there were statistically significant increases in TPC and AOC values after digestion for all pumpkin pestils compared to undigested samples (p<0.05). Drying process resulted in lower β-carotene content (between 32.15–61.11%) in pumpkin pestils; however, it increased the percentage of bioaccessible β-carotene (max 62.16%) in the pestil samples. Compared to HD and VCD techniques, pumpkin pestils dried with MD exhibited significantly higher TPC, AOC and β-carotene content (p<0.05). All of the pumpkin pestils except those dried by MD at 180 W contain HMF below the Turkish Standards Institute legal limit of 50 mg/kg. L* value of pestils were described adequately to the zero-and first-order kinetic models while a* and b* values were only fitted to zero-order model. In conclusion, the findings obtained in this study pointed out that drying processes (especially by MD method) increased the bioaccessibility of TPC, AOC, and β-carotene
Optimization of reduced calorie kiwi jam production: Physicochemical characterization and bioaccessibility in gastrointestinal conditions
No full textResponse surface methodology (RSM) was used to optimize the reduced calorie kiwi jam production under the effect of the independent variables including apple juice (X-1), stevia (X-2), and low methoxyl pectin (LMP) (X-3). The effect of these independent variables on physicochemical properties (brix, total acidity, pH), color values, total phenolic content (TPC), total antioxidant capacity (TAC), sugar profile, 5-Hydroxymethylfurfural (HMF) content, textural properties and sensorial acceptability of jam samples studied using Box-Behnken Design. Additionally the bioaccessibility of TPC and TAC for kiwi fruit and jam products was evaluated using standardized in vitro digestion model. Jam processing led to a significant reduction in TPC (51.38%-79.92%), and TAC for DPPH (85.59-96.97%), CUPRAC (60.10-82.79%), and FRAP (78.50-95.59) (p < 0.05). The TPC of all jam samples increased significantly, ranging from 1.14 to 2.67 times higher after in vitro digestion (p < 0.05), despite the total antioxidant capacity (TAC) showing variable results. The results also indicated that the addition of apple juice and stevia significantly enhanced the bioaccessibility of phenolic compounds (p < 0.05). The relationship between the responses (including brix, total acidity, pH, L*, a*, and b* values, firmness, stickiness, viscosity index, HMF, sucrose, TPC, CUPRAC, FRAP, and overall acceptability) and the variables was most accurately described using quadratic, reduced quadratic, and reduced cubic models with high R-2 values, as determined by RSM. The optimal condition for all responses with composite desirability of 0.877 was: 398.5 g of apple juice, 20.2 g of stevia, and 0.45 g of LMP. This study provides valuable insights into the formulation of healthier, low-calorie kiwi jams with enhanced nutritional and sensory properties, offering a promising approach for the food industry.University Students Research Projects Support Program - TUBIdot;TAK-2209-A - 1919B01200129
Evaluation of drying kinetics and quality parameters of rosehip pestils dried by three different methods
No full textBACKGROUND: Rosehip fruits cannot be eaten as entire fruits in their fresh feature so they processed into various products including pestils.OBJECTIVE: In the current work, rosehip pestil as a new healthy snack food was developed by using hot air (HA) drying at 55, 65 and 75 degrees C, vacuum (VC) drying at 55, 65 and 75 degrees C with 25 kPa and microwave (MCW) drying at 90 and 180W.METHODS: The effect of three different drying methods on drying kinetics and quality parameters i.e., total phenolic content (TPC), antioxidant capacity (AC), Hydroxymethylfurfural (HMF) formation, lycopene, beta-carotene content, element composition, color, texture and sensorial properties of rosehip pestils was studied.RESULTS: Wang and Singh model was best fitted for MCW drying at 90W, however Page and Modified Page models were best fitted for other drying conditions. The rosehip pestils dried by MCW drying method had highest drying rate, TPC, AC, lycopene and beta-carotene content, element concentration, color values, whereas their HMF content and sensorial properties were not acceptable. Sensory evaluation results indicated that rosehip pestils dried with HA was rated the most acceptable.CONCLUSIONS: It was concluded that rosehip pestil with its sensorial and nutritive properties could be an alternative product for the functional food market. However, it has been seen that the drying methods used alone have some disadvantages. For this reason, it may be possible to eliminate these disadvantages if hybrid drying methods (for example MCW drying followed by HA or VC drying) are preferred in future studies
Investigation about the potential of citron, sweet lemon, and sweet orange peels as herbal tea
No full textThis study investigated the sensorial quality, chemical composition, and bioactive potential of herbal teas made from the peels of sweet lemon (Citrus limetta Risso), sweet orange (Citrus sinensis (L.) Osbeck), and citron (Citrus maxima (Burm.) Merr) using freeze-drying, hot-air drying, and microwave drying. Sensory evaluation showed that teas from microwave-dried peels were most preferred, with microwave-dried sweet orange peel tea receiving the highest acceptability score (6.78/9). In contrast, freeze-dried sweet orange peel tea had the highest total phenolic content (843.40 mg gallic acid equivalent, GAE/L), while the microwave-dried version had the lowest (279.20 mg GAE/L). Hesperidin, protocatechuic acid, and chlorogenic acid were dominant in different citrus teas. Key volatiles included linalool in sweet lemon, naphthalene in sweet orange, and 2-furanmethanol derivative in citron. Sweet lemon peel tea had the highest antioxidant activity (0.90 mmol trolox equivalent, TE/L) and gastric bioaccessibility (0.22 mmol TE/L). Simulated digestion reduced most bioactive compounds; however, hesperidin, syringic acid, chlorogenic acid, protocatechuic acid, and luteolin-7-glycoside remained detectable depending on the tea type. Pesticide residues were found only in microwave-dried sweet orange peel tea, but remained below legal limits. While microwave drying enhanced sensory appeal, freeze-drying better preserved bioactive compounds. Overall, citrus peels show strong potential as sustainable raw materials for functional herbal teas
Investigation of drying kinetics and physicochemical properties of mulberry leather (pestil) dried with different methods
No full textThe effects of microwave (90 and 180 W), hot air (60 and 70 degrees C) and vacuum (60 and 70 degrees C with 250 mbar) drying techniques on drying characteristics, total phenolic content (TPC), antioxidant capacity (AC), color and texture of mulberry pestils were investigated. L*, b*, C*, and h degrees decreased while a* value was generally increased in pestils. Hardness, springiness, chewiness, and gumminess of the samples were found to be significantly different (p < 0.05). Between the applied seven thin layer drying models, Page and Modified Page were best fitted with the highest R-2 (0.9997) and the lowest values of RMSE (0.000927) and chi(2) (0.000011). Effective moisture diffusivity (D-eff) of pestils ranged from 4.42 x 10(-8) to 8.47 x 10(-7) m(2)/s. Drying treatments caused an increment in TPC (1.41%-57.13%) and AC (0.37%-72.79%). These highest results were both obtained from microwave 180 W (TPC: 209.14 mg GAE/100 g dw and AC: 181.37 mu mol TE/100 g dw). Practical applications Mulberry is a perishable fruit with several health benefits. It can be consumed raw or in the form of fruit leather (pestil), jam, jelly, marmalade. By pestil production, in which fruit pulp is dehydrated into leathery sheets, mulberry can be processed into a nonseasonal shelf life prolonged product for markets without the additon of preservatives. In this study, drying kinetics of mulberry pestil by microwave, hot air, and vacuum methods were evaluated via mathematical modeling. Page and Modified Page were the best thin layer drying models for pestil production. Drying characteristics were assessed for the development of food specific system in industrial usage and the simulation and optimization of the drying process. Drying treatmens affected texture and color of pestils significantly while exerting higher total phenolic content and antioxidant capacity when compared to non-dried formulation. Microwave was determined as a promising method to yield high-quality pestils with greater nutritional properties and the advantage of reduced drying times
Preservation of Beverage Nutrients by High Hydrostatic Pressure
No full textBeverages not only supply refreshment pleasure, but also provide a unique delivery system for nutrients such as vitamins, minerals, proteins, and others. Traditionally beverages have been preserved by the way of thermal processes including pasteurization and sterilization. On account of the negative effects of high process temperatures or times on nutritional value of beverages, alternative nonthermal processing techniques have been used in recent years. High hydrostatic pressure (HHP) is one of these nonthermal preservation techniques, which could be an alternative pasteurization and sterilization in the field of beverages as it has shown good results on minimizing the quality loss in terms of nutritional value. HHP method offers a quality assurance and safety in beverage processing without adding heat or preservatives. Moreover, the combination of HHP with other food preservation techniques has been studied in order to further extension of the shelf life of beverages without decreasing the nutritional value. HHP have been successfully implemented to a variety of beverages such as fruit and vegetable juices, caffeinated beverages, alcoholic beverages, and dairy beverages. The previous studies indicated that besides vitamins and proteins, phenolic compounds, aroma components, and color pigments were more retained in these beverages by HHP than thermal treatment. This chapter includes the effects of HHP application on the nutritional parameters of beverages
Drying characteristics, mineral content, texture and sensorial properties of pumpkin fruit leather
No full textThe objective of this study was to investigate the influences of hot air (HAD: 50, 60, 70 degrees C), vacuum (VD: 50, 60, 70 degrees C at 300 mbar) and microwave methods (MWD: 90, 180W) on drying characteristics, effective moisture diffusivity (D-eff), mineral content, texture, and sensorial properties of pumpkin pestils. MWD led to the highest drying rate and the lowest drying time in all methods. Page and Modified Page were ideally fitted to experimental results among seven thin layer drying models. Mineral content (Ca, K, Na, P, Mg, Fe, Zn, Cu, Mn) of the pestils showed higher values than non-dried (paste) mixture. Significant differences were determined between textural features of the pestils (p < 0.05). Furthermore, products dried with HAD and VD were preferred rather than MWD in terms of sensorial properties
Application of response surface methodology for optimisation of Cornelian cherry - Capia pepper leather dried in a heat pump drying system
No full textThe heat pump drying system was optimised for cornelian cherry-capia pepper leather production development using response surface methodology. The central composite design was used to optimise the process parameters in terms of drying time, coefficient of the performance of heat pump, coefficient of the performance of the whole system, specific moisture extracted ratio, energy consumption, drying rate and colour values. The optimal condition of independent variables was obtained as a cornelian cherry pulp concentration of 47.419% and drying temperature of 33.574°C with composite desirability of 0.846. Moreover, hydroxymethylfurfural (HMF) and effective moisture diffusivity (Deff) values of all runs were analysed. HMF was not determined in cornelian cherry-capia pepper leather. Deff values of cornelian cherry-capia pepper leather were between 1.026×10-9 - 1.532×10-9 m2s-1. The drying behaviour of cornelian cherry-capia pepper leather with optimal conditions acquired with the central composite design was evaluated with seven thin-layer drying models. The statistical parameters based on R2, root mean square of error and χ2 values were determined between 0.8267 to 0.9845, 0.004087 to 0.035626 and 0.000853 to 0.066247, respectively. Page and Modified Page models were assumed to represent the heat pump drying behaviour of the cornelian cherry-capia pepper leather in thin layers compared to the other models
Evaluation of the effect of sustainable drying techniques and intensification technologies on color profile of dehydrated fruits and vegetables
No full textThis research investigates the effects of various drying procedures and intensification technologies on the color profile of dried fruits and vegetables. The primary goal is to identify the most effective techniques for minimizing degradation, which is frequently caused by exposure to heat, oxygen, and longer drying durations, while retaining the original color of these products. Although conventional techniques like sun and hot air drying are often employed, enzymatic and non-enzymatic brownings usually cause a considerable loss of color. New technologies aim to better preserve the original color by cutting down on processing temperature and drying time. The paper also looks at the possibilities of hybrid drying approaches, which combine techniques such as infrared hot air drying and microwave hot air drying. These methods have been demonstrated to be especially successful in preserving color integrity and enhancing drying process effectiveness. The results highlight the vital significance that parameter optimization and drying technique selection play in maintaining the nutritional value and aesthetic appeal of dehydrated fruits and vegetables. This study emphasizes the significance of developing drying technologies to satisfy consumer desires for premium, aesthetically pleasing food goods, because color is a major factor in determining consumer acceptance and perceived product quality. With wider implications for food preservation and the food industry overall, this work helps to develop more effective and efficient drying processes by shedding light on how various drying techniques affect color retention
Investigation of the potential of citron, sweet lemon and sweet orange peels as herbal tea
No full textBu tez çalışmasında, tatlı limon, tatlı portakal ve ağaç kavunu kabukları kullanılarak farklı kurutma yöntemleri ile bitki çayı üretilmiş ve bu çayların duyusal, bazı kimyasal ve biyoaktif özellikleri incelenmiştir. Kurutma yöntemleri olarak dondurarak kurutma, sıcak hava ile kurutma (50ºC, 48 saat) ve mikrodalga kurutma (90 W, 1 saat) yöntemlerinden faydalanılmıştır. Dondurarak kurutulmuş tatlı portakal kabuğu çayı, fenolik madde miktarı açısından en yüksek değeri (843,4 mg GAE/L) gösterirken, mikrodalga ile kurutulmuş tatlı portakal kabuğu çayı en düşük fenolik madde miktarına (279,2 mg GAE/L) sahip olmuştur. Antioksidan aktivite açısından tatlı limon kabuğu çayı, sindirilmemiş çaylarda 0.895 mmol TE/L, sindirilmiş örneklerde ise 0.222 mmol TE/L ile (gastrik fazda) en yüksek değerlere ulaşmıştır. Sindirim simülasyonları, tüm örneklerde fenolik madde ve antioksidan aktivitenin önemli ölçüde azaldığını, ancak bazı bileşenlerin sindirimin ileri aşamalarında korunduğunu göstermiştir. Duyusal analiz sonuçlarına göre, mikrodalga ile kurutulmuş çaylar tat ve aroma açısından en beğenilen çaylar olmuş ve tatlı portakal kabuğu çayı 6.78 genel beğeni puanı ile en yüksek skoru almıştır. Uçucu bileşen analizlerinde, tatlı limon kabuğu çayında en yüksek konsantrasyona sahip bileşen linalool (117,744 µg/L), tatlı portakal kabuğu çayında naftalin (37,081 µg/L) ve ağaç kavunu kabuğu çayında 2-Furanmetanol 5-eteniltetrohidro-.alfa.,.alfa.,5-trimetil-, cis- (77,460 µg/L) olarak tespit edilmiştir. Bireysel fenolik bileşik analizlerinde, hesperidin (11,278 µg/mL) tatlı limon kabuğu çayında en baskın bileşen olarak bulunmuştur. Ayrıca, ağaç kavunu kabuğu çayında protokatekuik asit (16,585 µg/mL) ve klorojenik asit (1,700 µg/mL) gibi fenolik maddeler de tespit edilmiştir. Ayrıca, pestisit analizlerinde tatlı portakal kabuğu çayında 0.137 mg/kg azoksistrobin tespit edilmiştir. Sonuç olarak, mikrodalga kurutma yöntemi tüketici beğenisi açısından en uygun yöntem olarak, liyofilizasyon tekniği ise biyoaktivite açısından en iyi sonuçları veren yöntem olarak öne çıkmıştır. Narenciye kabukları, atık yönetiminde değerlendirilebilecek önemli bir kaynak olup, bu çalışmanın sürdürülebilirlik ve sağlıklı ürün geliştirme açısından katkı sağlayacağı düşünülmektedir.In this thesis, herbal teas were produced using the peels of sweet lemon, sweet orange, and citron through different drying methods, and their sensory, chemical, and bioactive properties were analyzed. The drying methods used were freeze-drying, hot air drying (50°C for 48 hours), and microwave drying (90 W for 1 hour). The freeze-dried sweet orange peel tea showed the highest phenolic content (843.4 mg GAE/L), while the microwave-dried sweet orange peel tea had the lowest phenolic content (279.2 mg GAE/L). In terms of antioxidant activity, the sweet lemon peel tea had the highest values in both undigested (0.895 mmol TE/L) and digested samples (0.222 mmol TE/L in the gastric phase). The digestion simulations demonstrated that, phenolic content and antioxidant activity significantly decreased in all samples, although some compounds were preserved in later digestion stages. Sensory analysis results indicated that, the microwave-dried teas were the most preferred in terms of taste and aroma, with the sweet orange peel tea scoring the highest (6.78) in overall preference. In the volatile compound analysis, linalool (117,744 µg/L) was the most abundant compound in sweet lemon peel tea, naphthalene (37,081 µg/L) in sweet orange peel tea, and 2-Furanmethanol 5-ethenyltetrahydro-.alpha.,.alpha.,5-trimethyl-, cis- (77,460 µg/L) in pomelo peel tea. In the individual phenolic compound analysis, hesperidin (11,278 µg/mL) was found to be the dominant compound in sweet lemon peel tea, while protocatechuic acid (16,585 µg/mL) and chlorogenic acid (1,700 µg/mL) were detected in pomelo peel tea. Additionally, pesticide analysis revealed 0.137 mg/kg of azoxystrobin in sweet orange peel tea. In conclusion, the microwave drying method was identified as the most suitable method in terms of consumer preference, while the freeze-drying technique provided the best results for bioactivity. Citrus peels represent a valuable resource for waste management, and this study is expected to contribute to sustainability and healthy product development
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