Impact of sulfite use and acidification on chemical quality components in thermally processed watermelon juices.

The present study compared pasteurized and reconstituted (from vacuum-concentrated) watermelon juices with sulfite use (∼40 mg/L) and acidification (pH = 4.2) to fresh watermelon juices. The products were evaluated for phenolics, free amino acids, carotenoids, sugars, organic acids, and alcohols by high-performance liquid chromatography-HPLC and the volatile profile by headspace-gas chromatography/mass spectrometry(HS-GC/MS). Pasteurization had no significant impact on most of the chemical components. Furthermore, it potentiated typical watermelon aromas (E,E)-2,6-nonadienal, (Z)-3-nonen-1-ol, 4-hexen-1-ol, (E,Z)-3,6-nonadien-1-ol, 6-amino-2-methyl-2-heptanol, (E)-6-nonenal, (E)-2-nonenal, pentanal, nonanal and 1-nonanol), without off-flavor compounds formation. On the other hand, the reconstituted juice showed reduced amino acids (serine, glutamine, and tryptophan), phenolics (epicatechin gallate, myricetin, and cis-resveratrol), carotenoids (lycopene, ß-carotene, and violaxanthin) and most volatile compounds. Our results showed that sulfite and acidification could maintain watermelon juice's nutritional and quality parameters after pasteurization. The vacuum concentration and reconstitution processes negatively impacted the evaluated compounds. Our findings contribute to improving thermal processes in watermelon juices for better preservation of nutrients, flavor, and bioactive compounds.

Effect of commercial yeasts (Saccharomyces cerevisiae) on fermentation metabolites, phenolic compounds, and bioaccessibility of Brazilian fermented oranges.

Brazil is the largest producer of oranges worldwide, as well as one of the largest producers of orange juice. Alcoholic fermented beverages have been considered a marketable alternative for oranges. In this study, four S. cerevisiae commercial yeasts were evaluated for metabolites generated during orange juice (cv. 'Pêra D9') fermentation. Alcohols, sugars, and organic acids were evaluated by HPLC-DAD-RID during fermentation, and phenolic compounds were analyzed in fermented orange. Orange juice and fermented oranges were also subjected to digestion simulations. The yeasts presented an adequate fermentation activity, based on sugar consumption, and high ethanol (>10.5%) and glycerol (4.8-5.5 g/L) contents. The yeast strains T-58 and US-05 produced high levels of lactic acid. Phenolic compounds and antioxidant activity did not differ amongst yeasts, presenting hesperidin levels between 115 and 127 mg/L, respectively. The fermented orange showed a >70% bioaccessibility, compared to juice, especially for catechin, epigallocatechin-gallate, procyanidin-B2, rutin, and procyanidin-B1.

Sensorial characteristics and chemical composition of manufactured coalho cheese / Estudo das características sensoriais e da composição química de queijo de coalho industrializado

This study evaluated the defining features of manufactured coalho cheese by Quantitative DescriptiveAnalysis (QDA), as acceptability test, purchasing intention and physical-chemical analyses. The acceptabilitytest was carried out by 50 consumers. The sample A was assessed on the features as typical curd cheese aroma,typical curd cheese taste, while sample B was evaluated on its yellow color and chewiness. Characteristicsas holes, fatty taste, and acid taste were not relevant for qualifying any of the samples. Sample C was highlyscored on buttery aroma (5.4) and salty taste (4.6). Sample A received the highest acceptance score onappearance (7.14) and taste (7.02) features, and therefore it got the highest purchasing intention score,being I would certainly buy (40.0%) and I would probably buy (32.0%). The samples showed a highhumidity varying from 51.98% (sample A) to 53.25% (sample C). Chloride contents in sample A was 1.37%,and acidity of 0.91 (g% of lactic acid) and pH 6.0. Presumably, the salt contents and the percentage of acidfound in sample A are close to the desirable rates for coalho cheese.

O trabalho teve como objetivo avaliar as características de queijo de coalho industrializado utilizando aAnálise Descritiva Quantitativa (ADQ), teste de aceitabilidade, intenção de compra e análises físico-químicas.O teste de aceitabilidade foi realizado por 50 consumidores. A amostra A foi analisada nos aspectos como:aroma típico de queijo de coalho e sabor típico de queijo de coalho; a amostra B foi caracterizada pelacoloração amarela e qualidade de mastigação. Os atributos, como olhaduras, sabor de gordura e sabor ácidonão foram relevantes na caracterização das amostras analisadas. A amostra C recebeu maior pontuaçãonos atributos como aroma de manteiga (5,4) e sabor salgado (4,6). A amostra A obteve a maior média deaceitabilidade para aparência (7,14) e sabor (7,02) e, consequentemente, a maior intenção de compra nosconceitos certamente compraria (40,0%) e provavelmente compraria (32,0%). As amostras apresentaramalto teor de umidade, variando de 51,98% (amostra A) 53,25% (amostra C). A amostra A apresentou teorde cloreto de 1,37%, acidez de 0,91 (g% de ácido láctico) e pH 6,0. O teor de sal e a porcentagem de acidezencontrados na amostra A estão próximos aos valores desejáveis para queijo de coalho.