ABSTRACT. This study examined biochemical changes associated with chilling injury (CI) in sweet potato roots stored at low temperatures and reconditioned at ambient temperature. Sweet potato cultivars BRS Amélia and BRS Rubissol were stored at 6 or 13°C for 4 days at ambient temperature (“ambient reconditioning”: 21 ± 2°C). CI on the outer surface of the roots occurred earlier in BRS Amélia than in BRS Rubissol. The CI index on the inner surface of the BRS Amélia was higher when it was stored at 6°C for 40 + 4 days. BRS Amélia showed higher proline content and electrolyte leakage when stored at 6°C. Ascorbate peroxidase was induced by storage at 6°C for 30 + 4 days in BRS Amélia and from 40 + 4 days in BRS Rubissol. The malondialdehyde and phenolic compounds of BRS Rubissol increased during storage at 6°C. CI in both cultivars was associated with increased peroxidase and polyphenol oxidase activities. Storage of sweet potato cultivars at 6°C for 50 + 4 days caused severe damage to the roots. Cultivars BRS Amélia and BRS Rubissol showed similar symptoms of CI and can be characterized as being sensitive to low temperatures.

ABSTRACT. Since the composition of honey varies with the species of bee as well as flowering and geographical aspects, this study aimed to evaluate the physicochemical and bioactive properties of Apisand stingless bees’honey from the Brazilian Caatinga. Samples of different species of Apis mellifera L.Meliponini (Melipona subnitida, Frieseomellita varia, Melipona mandacaia, Plebeia sp.) and Apis mellifera L.werecollected from honey producersin the state of Rio Grande do Norte. Honey from A. mellifera and stingless bees showed physicochemical differences in some parameters, especially in moisture, free acidity, HMF, water activity, sugars and electric conductivity. There were no differences in color between honeys from A. mellifera and stingless bees. Honeys fromPlebeia sp., F. varia and A. mellifera showed higher antioxidant capacity followed by honeys fromM. mandacaia and M. subnitida. Flavonoids had little influence on the differentiation of antioxidant activities of stingless bees, while the opposite occurred with the phenolic content, where honeys with the highest levels of phenolic also showed higher antioxidant capacity. ABSTRACT aspects beeshoney Caatinga LMeliponini L Meliponini subnitida sp. sp Lwerecollected werecollected Norte A parameters moisture acidity HMF activity conductivity F fromM M content

ABSTRACT Nasturtium (Tropaeolum majus) is an ornamental and medicinal plant that has edible flowers. Drought and salt stress decrease flower production and quality, including affecting sugar metabolism and ethylene production. Ethylene can accelerate the nasturtium senescence process, decreasing its postharvest quality. The use of polyamines, mainly spermine, may be a strategy for reducing the harmful effects of these stresses on the metabolism of sugars and phenolic compounds and for decreasing the production of ethylene, which accelerates senescence, in nasturtium flowers. Therefore, the objective here was to evaluate the role of spermine application on sugar and phenolic compounds and on ethylene production in nasturtium flowers grown under drought and salt stress. Two experiments were performed in isolation and at the same time in order to achieve this. Spermine down-regulated ethylene production and up-regulated the content of sugars and phenolic compounds on nasturtium flowers grown under drought and saline stress. Sugars and phenolic compounds down-regulated ethylene production in nasturtium flowers. Spermine can be used to mitigate the harmful effects of drought and salt stress on nasturtium flowers by increasing sugar and phenolic compounds and decreasing ethylene production. Tropaeolum majus quality process polyamines Therefore this downregulated down regulated upregulated up

Abstract Sweet potato fried chips have great acceptance and high market value. Sprouting and fresh mass loss of tuberous roots during storage compromise the quality of the processed products. The objective of this work was to evaluate the effect of 1-Methylcyclopropene (1-MCP), amino-oxyacetic acid (AOA), and ethylene on the physico-chemical quality of fresh sweet potato and its relationship with fried color score in processed chips of cv. BRS Rubissol stored at room temperature. During storage, the weight loss, sprouts number, dry matter content, non-enzymatic browning, protein content, soluble phenols fraction, reducing sugars, total amino acids, pH, soluble solids (SS), titratable acidity (TA) and SS/TA ratio were evaluated. The sweet potato roots cv. BRS Rubissol present good potential for processing as fried chips. 1-MCP and AOA treatments reduced the root sprouting, physico-chemical quality was maintained in all treatments and the fried chips showed less browning in all treatments with storage. Since the sprouting process compromises the storage of roots, AOA and 1-MCP treatments may be applied to extend the shelf-life of roots and improve the processing potential.