Calçots Case Study
2.1 Plant material
Calçots (Allium cepa L.) were provided by the ‘Cooperativa of Valls’ (Tarragona, Spain) at commercial maturity. The calçots had the European quality label Protected Geographical Indication ‘Calcot de Valls’. They were cultivated in La Masó in northeast of Spain (41º13’47’’N, 01º13’12’’E), during crop growing season of 2014 and 2015. In August 2014, the bulbs of ‘Blanca Tardana de Lleida’ onion were transplanted at a density of 8,000 plants per hectare. The resprouts arising in the autumn were covered with soil three times to increase the length of the edible white part. In February, the plants were manually harvested.
The minimal processing was carried out by manual processing included cutting of calçot 4 cm over the last …show more content…
At each disinfection treatment, minimally processed calçots were immersed in 10 L disinfectant solution at room temperature under continuous agitation (x rpm) for 60 s. For all washing solutions, pH and oxidation-reduction potential (ORP) were determined before and after calçot treatment (Table 1). Free chlorine and peracetic acid was determined using a free and total photometer (HI 93734, Hanna Instruments, Eibar, Spain). ORP and pH were determined using a pH/ion/conductivity meter (Model GLP-22, Crison), with a pH electrode (Crison, 52-01) or an ORP electrode (Crison, platinum Ag/AgCl electrode 52-61). In addition the microbial load of each washing solution after treatment was evaluated. To carry out such determinations, 1 mL of each washing solution was added to 9 mL of buffered peptone water (BPW, Oxoid). Afterwards the samples were rinsed with water, centrifuged in X centrifuge (Marrodan, Binefar, Spain) for 95 s and dried at room temperature before packaging. The calçots were packaged in polystyrene trays with retractable film and stored at 4 °C for 15 d. The microbiological and quality determinations were carried out after …show more content…
TCD was calculated as Martín-Diana et al. (2007) described:
TCD=〖[(L_f^*-L_i^* )^2+(a_f^*-a_i^* )^2+(b_f^*-b_i^* )^2]〗^(1/2) (2) where i = initial (without disinfection) and f = final.
2.8 Assessment of overall visual quality
The assessment was carried out as described Altisent, Plaza, Alegre, Viñas, & Abadias (2014). The visual quality was determined by an untrained panel based on the following hedonic scale: 9 = excellent; 7 = very good; 5 = good, limit of marketability; 3 = fair, limit of usability; and 1 = poor, inedible.
2.9 Statistical analysis
Results were expressed as mean ± standard deviation of three independent determinations. Significant differences between results were calculated by one-way analysis of variance (ANOVA). Differences were considered to be significant at P<0.05 (95 % confidence level). Significance of differences among means was determined by Tukey´s test and t-tests. All statistical analyses were performed with JMP 8 software (SAS Institute Inc., Cary, NC,
Calçots (Allium cepa L.) were provided by the ‘Cooperativa of Valls’ (Tarragona, Spain) at commercial maturity. The calçots had the European quality label Protected Geographical Indication ‘Calcot de Valls’. They were cultivated in La Masó in northeast of Spain (41º13’47’’N, 01º13’12’’E), during crop growing season of 2014 and 2015. In August 2014, the bulbs of ‘Blanca Tardana de Lleida’ onion were transplanted at a density of 8,000 plants per hectare. The resprouts arising in the autumn were covered with soil three times to increase the length of the edible white part. In February, the plants were manually harvested.
The minimal processing was carried out by manual processing included cutting of calçot 4 cm over the last …show more content…
At each disinfection treatment, minimally processed calçots were immersed in 10 L disinfectant solution at room temperature under continuous agitation (x rpm) for 60 s. For all washing solutions, pH and oxidation-reduction potential (ORP) were determined before and after calçot treatment (Table 1). Free chlorine and peracetic acid was determined using a free and total photometer (HI 93734, Hanna Instruments, Eibar, Spain). ORP and pH were determined using a pH/ion/conductivity meter (Model GLP-22, Crison), with a pH electrode (Crison, 52-01) or an ORP electrode (Crison, platinum Ag/AgCl electrode 52-61). In addition the microbial load of each washing solution after treatment was evaluated. To carry out such determinations, 1 mL of each washing solution was added to 9 mL of buffered peptone water (BPW, Oxoid). Afterwards the samples were rinsed with water, centrifuged in X centrifuge (Marrodan, Binefar, Spain) for 95 s and dried at room temperature before packaging. The calçots were packaged in polystyrene trays with retractable film and stored at 4 °C for 15 d. The microbiological and quality determinations were carried out after …show more content…
TCD was calculated as Martín-Diana et al. (2007) described:
TCD=〖[(L_f^*-L_i^* )^2+(a_f^*-a_i^* )^2+(b_f^*-b_i^* )^2]〗^(1/2) (2) where i = initial (without disinfection) and f = final.
2.8 Assessment of overall visual quality
The assessment was carried out as described Altisent, Plaza, Alegre, Viñas, & Abadias (2014). The visual quality was determined by an untrained panel based on the following hedonic scale: 9 = excellent; 7 = very good; 5 = good, limit of marketability; 3 = fair, limit of usability; and 1 = poor, inedible.
2.9 Statistical analysis
Results were expressed as mean ± standard deviation of three independent determinations. Significant differences between results were calculated by one-way analysis of variance (ANOVA). Differences were considered to be significant at P<0.05 (95 % confidence level). Significance of differences among means was determined by Tukey´s test and t-tests. All statistical analyses were performed with JMP 8 software (SAS Institute Inc., Cary, NC,