Keçiboynuzu pekmezi üretiminde ekstraksiyon ve evaporasyon aşamalarında ohmik ısıtma desteğinin uygulanabilirliğinin incelenmesi
Küçük Resim Yok
Tarih
2023
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu tez çalışmasında, keçiboynuzu pekmezi eldesinde ısıtma, ekstraksiyon ve evaporasyon aşamalarında güncel bir alternatif ısıtma teknolojisi olan ohmik ısıtma desteğinin uygulanabilirliği incelenmiştir. Isıtma aşamasında, keçiboynuzu dilimleri-su karışımı 5 farklı voltaj gradyanı (10, 12.5, 15, 17.5 ve 20 V/cm) ve 2 farklı dalga tipi (sinüs ve kare) uygulanması ile hedef ekstraksiyon sıcaklığına (40°C) ohmik ısıtılmıştır. Ohmik ısıtma işlem süresinin uygulanan voltaj gradyanı arttıkça azaldığı tespit edilmiştir (p<0.05). Kare dalga tipinin sinüse kıyasla daha kısa işlem süreleri sağlayabildiği belirlenmiştir (p<0.05). İşlem süresinin kısa olduğu tüm işlem koşullarında, karışımın sıvı kısmının suda çözünür kuru madde (SÇKM), toplam fenolik madde (TFM) içerikleri ve bazı renk özelliklerindeki (b*, ?E ve ?C) değişimlerin düşük olduğu saptanmıştır (p<0.05). Kare dalga tipinde düşük voltaj gradyanlarında yüksek enerji ve ekserji verimlilikleri elde edilmiştir (p<0.05). Karışımın EEİ değerlerinin sıcaklık arttıkça arttığı belirlenmiştir. En uygun ohmik ısıtma koşulu 12.58 V/cm ve kare dalga tipi olarak tespit edilmiştir. İlk aşamada hedef sıcaklığa ulaşıldıktan sonra ikinci aşamada ekstraksiyon işlemi ile şıra eldesi gerçekleştirilmiştir. Ohmik ekstraksiyonda (OE), 3 farklı su/ keçiboynuzu dilimleri oranı (4, 7 ve 10), 3 farklı sıcaklık (40, 45 ve 50°C), 3 farklı voltaj gradyanı (6, 8 ve 10 V/cm) ve 3 farklı frekansın (50, 875 ve 1700 Hz) etkisi incelenmiştir. Su/keçiboynuzu dilimleri oranı azaldıkça SÇKM içeriği, toplam antioksidan aktivite ve b*, ?E, ?C ve kroma renk değerlerinin arttığı tespit edilmiştir (p<0.05). TFM verimi ise ekstraksiyon sıcaklığı arttıkça ve uygulanan frekans değeri azaldıkça artmıştır (p<0.05). Uygulanan frekansın performans özellikleri üzerine etkili olmadığı (p>0.05) belirlenmiştir. Su/keçiboynuzu dilimleri oranı, uygulanan voltaj ve ekstraksiyon sıcaklığı azaldıkça enerji ve ekserji verimliliklerinin arttığı, iyileştirme potansiyelinin ise azaldığı saptanmıştır (p<0.05). Şıra eldesi işlemi için en uygun OE koşulu 4/1 su/keçiboynuzu dilimleri oranı, 52.93 Hz, 10 V/cm, 40°C olarak tespit edilmiştir. Geleneksel ekstraksiyon yöntemi ile elde edilen şıranın TFM verimi ve toplam antioksidan aktivitesinin OE ile elde edilenden daha düşük olduğu (p<0.05), SÇKM ve renk özelliklerinin ise benzer olduğu belirlenmiştir (p>0.05). Ohmik ısıtma desteğinin ekstraksiyon işleminin enerji ve ekserji verimliliklerini sırasıyla 3.11 ve 4.73 kat arttırdığı saptanmıştır. Son aşamada vakumlu ohmik evaporasyon (VOE) işlemi şıranın konsantre edilmesinde kullanılmış, geleneksel vakumlu evaporasyon (GE) yöntemine kıyasla işlem süresinin önemli ölçüde kısaltılabildiği belirlenmiştir (p<0.05). VOE ile elde edilen pekmezlerin GE ile elde edilene kıyasla daha yüksek TFM içeriği, pH değeri ve sakkaroz içeriğine sahip olduğu, diğer yandan daha düşük renk değişiminin ve hidroksi metil furfural (HMF) oluşumunun gerçekleştiği tespit edilmiştir (p<0.05). Her iki yöntemle elde edilen pekmezlerin SÇKM içeriklerinin ve toplam antioksidan aktivitelerinin ise benzer olduğu saptanmıştır (p>0.05). Bu tez çalışmasında elde edilen verilerin keçiboynuzu pekmezi üretiminin ısıtma, ekstraksiyon ve evaporasyon aşamalarında ohmik ısıtma desteğinin kullanılmasında gıda endüstrisine ve literatüre değerli katkı sağlayacağı düşünülmektedir.
In this thesis, the applicability of the assistance ohmic heating, which is the novel alternative heating method, in the heating, extraction, and evaporation stages of the production of carob molasses was investigated. In the heating stage, the carob slices-water mixture was ohmic heated to the target extraction temperature (40°C) by application of 5 different voltage gradients (10, 12.5, 15, 17.5, and 20 V/cm) and 2 different wave types (sine and square). The ohmic heating time decreased as the applied voltage gradient increased (p<0.05). The square wave type resulted in lower treatment times compared to the sine wave (p<0.05). For the conditions having short process times, the changes in the water-soluble solid (WSS) content, total phenolic content (TPC) yields, and color properties of the solutions were low (p<0.05). The energy and exergy efficiencies were high in square wave type with low voltage gradients (p<0.05). The EEC values of the mixture increased as the temperature increased. The optimum ohmic heating condition for the heating stage was determined as 12.58 V/cm and square wave type. After reaching the target temperature in the first stage, the wort was obtained with a 1-hour extraction process in the second stage. In ohmic extraction (OE), the effect of 3 different water/carob slices ratio (4, 7, and 10), 3 different temperatures (40, 45, and 50°C), 3 different voltage gradients (6, 8, and 10 V/cm) and 3 different frequency (50, 875 and 1700 Hz) were examined. As the ratio of water/carob slices decreased, WSS content, total antioxidant activity, b*, ?E, ?C, and chroma values increased (p<0.05). As the extraction temperature increased or the applied frequency value decreased TPC efficiency increased (p<0.05). The applied frequency did not affect the performance characteristics (p>0.05). The energy and exergy efficiencies were increased or the improvement potential decreased as the water/carob slices ratio, applied voltage, and extraction temperature decreased (p<0.05). The optimum OE condition was determined as 4/1 water/carob slices ratio, 52.93 Hz, 10 V/cm, 40°C. It was determined that the TPC yield and total antioxidant activity obtained by the conventional extraction were lower than those obtained by OE (p<0.05) while the WSS content and color characteristics of the wort were similar (p>0.05). Ohmic heating assistance increased the energy and exergy efficiencies of the extraction process by 3.11 and 4.73 times, respectively. In the last stage, vacuum ohmic evaporation (VOE) was used to concentrate the wort, and the processing time was shortened significantly compared to the conventional method (p<0.05). The molasses obtained by VOE had higher TPC content, L* color value, pH value, and sucrose content while it has lower color changes and hydroxy methyl furfural (HMF) formation than the conventional one (p<0.05). However, it was found that the WSS value and total antioxidant activities were similar (p>0.05). It is thought that the results obtained in this thesis will make a valuable contribution to the food industry and the literature on the use of ohmic heating in the heating, extraction, and evaporation stages of the production of carob molasses.
In this thesis, the applicability of the assistance ohmic heating, which is the novel alternative heating method, in the heating, extraction, and evaporation stages of the production of carob molasses was investigated. In the heating stage, the carob slices-water mixture was ohmic heated to the target extraction temperature (40°C) by application of 5 different voltage gradients (10, 12.5, 15, 17.5, and 20 V/cm) and 2 different wave types (sine and square). The ohmic heating time decreased as the applied voltage gradient increased (p<0.05). The square wave type resulted in lower treatment times compared to the sine wave (p<0.05). For the conditions having short process times, the changes in the water-soluble solid (WSS) content, total phenolic content (TPC) yields, and color properties of the solutions were low (p<0.05). The energy and exergy efficiencies were high in square wave type with low voltage gradients (p<0.05). The EEC values of the mixture increased as the temperature increased. The optimum ohmic heating condition for the heating stage was determined as 12.58 V/cm and square wave type. After reaching the target temperature in the first stage, the wort was obtained with a 1-hour extraction process in the second stage. In ohmic extraction (OE), the effect of 3 different water/carob slices ratio (4, 7, and 10), 3 different temperatures (40, 45, and 50°C), 3 different voltage gradients (6, 8, and 10 V/cm) and 3 different frequency (50, 875 and 1700 Hz) were examined. As the ratio of water/carob slices decreased, WSS content, total antioxidant activity, b*, ?E, ?C, and chroma values increased (p<0.05). As the extraction temperature increased or the applied frequency value decreased TPC efficiency increased (p<0.05). The applied frequency did not affect the performance characteristics (p>0.05). The energy and exergy efficiencies were increased or the improvement potential decreased as the water/carob slices ratio, applied voltage, and extraction temperature decreased (p<0.05). The optimum OE condition was determined as 4/1 water/carob slices ratio, 52.93 Hz, 10 V/cm, 40°C. It was determined that the TPC yield and total antioxidant activity obtained by the conventional extraction were lower than those obtained by OE (p<0.05) while the WSS content and color characteristics of the wort were similar (p>0.05). Ohmic heating assistance increased the energy and exergy efficiencies of the extraction process by 3.11 and 4.73 times, respectively. In the last stage, vacuum ohmic evaporation (VOE) was used to concentrate the wort, and the processing time was shortened significantly compared to the conventional method (p<0.05). The molasses obtained by VOE had higher TPC content, L* color value, pH value, and sucrose content while it has lower color changes and hydroxy methyl furfural (HMF) formation than the conventional one (p<0.05). However, it was found that the WSS value and total antioxidant activities were similar (p>0.05). It is thought that the results obtained in this thesis will make a valuable contribution to the food industry and the literature on the use of ohmic heating in the heating, extraction, and evaporation stages of the production of carob molasses.
Açıklama
Anahtar Kelimeler
Gıda Mühendisliği, Food Engineering
