Akademik Veri Yönetim Sistemi
GIDA / THE JOURNAL OF FOOD, cilt.42, sa.2, ss.169-176, 2017 (Hakemli Dergi)
Bu araflt›rmada iki farkl› kurutma yöntemi (konveksiyonel (70 °C) ve dondurarak kurutma (-66 °C’de 5 mtorr bas›nçta) ile kurutulan karpuzlar›n fiziksel, kimyasal ve duyusal özellikleri karfl›laflt›r›lm›flt›r. Üretim yöntemlerinin kurutulmufl karpuz üzerindeki etkisini belirlemek amac›yla pH, titrasyon asitli¤i, renk, toplam kurumadde, su aktivitesi, toplam karotenoid miktar›, likopen, β-karoten, hidroksimetilfurfural (HMF), askorbik asit içeri¤i ve duyusal de¤erlendirilmesi yap›lm›flt›r. Konveksiyonel kurutulmufl karpuzlarda daha fazla HMF oluflurken dondurularak kurutulanlarda ise likopen içeri¤inde daha fazla azalmalar tespit edilmifltir. Dondurularak kurutulan örneklerin ölçülen renk de¤erlerinden L* ve Hue* de¤erleri artm›fl, a* de¤eri azalm›fl ve tazelerine göre en çok renk de¤iflimi (?E*) dondurularak kurutulmufl örneklerde görülmüfltür. Konveksiyonel kurutulmufl örneklerin toplam karotenoid içerikleri tazeye göre daha yüksek (284.43 mg/kg-5.30 kat fazla), askorbik asit içerikleri ise tazelerine göre daha az (9.63 mg/kg-3.38 kat› azalma) tespit edilmifltir. Dondurularak kurutulmufl örneklerde ise, askorbik asit de¤eri tazeye göre daha yüksek (245.13 mg/kg-7.51 kat› art›fl) belirlenmifltir. Kurutulmufl karpuzlar›n duyusal de¤erlendirmesinde renk bak›m›ndan konveksiyonel kurutulmufl örnekler yüksek puan al›rken, tat bak›m›ndan en yüksek be¤eniyi dondurularak kurutulan örnekler alm›flt›r.
In this study, water melons dried with two different methods (conventional (70 °C) and freeze-drying (66 °C-5 mtorr)) were compared by physical, chemical and sensorial properties of them. To determine the effect of drying methods on pH, titration acidity, color, total dry matter, water activity, total carotenoid contents, lycopene, β-carotene, hydroxymethylfurfural (HMF), ascorbic acid and sensorial evolution of dried watermelon samples were carried out. While HMF formation in conventional-dried samples were higher than freeze drying samples, lycopene degradation of freeze-dried samples were higher than conventional dried samples. The color values of L* and Hue* of the freeze-dried samples increased, but a* value decreased. In addition, according to the color values of fresh watermelon sample, the highest color changing (?E*) was determined for freeze-dried samples. The total carotenoid contents of conventional-dried samples were determined higher (284.33 mg/kg-higher 5.30 times) than freeze-dried samples. While ascorbic acid contents of the conventional-dried samples were decreasing (9.63 mg/kg-lower 3.38 times), the freeze-dried samples were increasing (245.13 mg/kg- higher 7.51 times) according to the fresh watermelon samples. According to sensorial evaluation of dried watermelon samples, the highest color score obtained for conventional-dried, while the highest taste score obtained for freeze-dried.