Faculty of Food Technology and Biotechnology, University of Zagreb
Abstract
Jalapeño peppers incur texture changes during thermal processing due to loss of turgor pressure, tissue softening, and pectin solubility in the cell wall, which affects their quality and acceptability as a processed product among consumers. The objective of this work is to evaluate the effect of stepwise blanching with calcium chloride solution on firmness, calcium absorption and microstructural changes of jalapeño peppers. Batches of 1 kg of pepper halves were blanched at 65 °C for 4 min at different concentrations of CaCl2 (0, 0.075, 0.15 and 0.3 mol/L). After blanching, the peppers were removed, placed in plastic bags and submerged in a water bath at 65 °C for different holding times (0, 15, 30 and 45 min). Then the peppers were blanched again in an acidified solution at 96 °C for 3 min to remove enzymatic activity. Afterwards, peppers were packed in glass containers with brine at 95 °C and pasteurized at 85 °C for 10 min. The product was stored for 10 days at room temperature, then analyzed for texture, calcium absorption, pH, acidity, and microstructural changes. Results showed that CaCl2 concentration and blanching improved firmness with a maximum value of 3.68 N, a 4.3-fold increase over control. Calcium absorption increased with CaCl2 concentration reaching a maximum of 0.68 g of Ca2+ per kg of samples. Microscopy showed reduced cell wall damage in the samples that were blanched in 0.3 mol/L of CaCl2 at 45 min of holding time. The optimum processing conditions determined in thisstudy can be used for improving the firmness of peppers.Tijekom toplinske obrade mijenja se tekstura „jalapeño” paprika zbog gubitka turgora, mekšanja tkiva i topljivosti pektina u staničnim stijenkama, što utječe na njihovu kakvoću i prihvatljivost među potrošačima. Svrha je ovoga rada bila procijeniti učinak postupnog blanširanja u otopini kalcijeva klorida na čvrstoću tkiva, apsorpciju kalcija i mikrostrukturalne promjene „jalapeño” paprika. Šarže od 1 kg polovica paprika blanširane su 4 minute na 65 °C pri različitim koncentracijama CaCl2 (0; 0,075; 0,15 i 0,3 mol/L). Nakon blanširanja paprike su stavljene u plastične vrećice i potopljene u vodenu kupelj na 65 °C tijekom 0, 15, 30 i 45 min. Zatim su radi inaktivacije enzima 3 minute blanširane u zakiseljenoj otopini pri 96 °C, te pakirane u staklenke s rasolom (pri 95 °C) i pasterizirane na 85 °C tijekom 10 min. Naposljetku su 10 dana skladištene na sobnoj temperaturi, nakon čega je analizirana njihova tekstura, apsorpcija kalcija, pH, kiselost i mikrostrukturalne promjene. Rezultati pokazuju da CaCl2 i blanširanje poboljšavaju čvrstoću tkiva 4,3 puta (na maksimalnih 3,68 N), u usporedbi s kontrolnim uzorkom. Povećanjem koncentracije CaCl2 povećala se apsorpcija kalcija (maksimalno 0,68 g Ca2+/kg paprika). U uzorcima blanširanim 45 min u otopini CaCl2, koncentracije 0,3 mol/L, mikroskopski je utvrđeno manje oštećenje staničnih stijenki. Stoga je zaključeno da se čvrstoća paprika može poboljšati optimiranjem uvjeta prerade
