Bioproduction of α-terpineol and R-(+)-limonene derivatives by terpene-tolerant ascomycete fungus as a potential contribution to the citrus value chain.

AIMS: The aims of this article were to select fungal species with high tolerance and high growth rate in mediums supplemented with limonene and citrus essential oils (CEOs), and to test the bioconversion capability of the chosen isolates for the bioproduction of aroma compounds. METHODS AND RESULTS: Based on the use of predictive mycology, 21 of 29 isolates were selected after assaying R-(+)-limonene and CEO tolerance (10 g l-1 ). With a dendrogram divisive coefficient of 0·937, the subcluster two with isolates Aspergillus niger LBM 055, Penicillium sp. LBM 150, Penicillium sp. LBM 151 and Penicillium sp. LBM 154 gathered the highest tolerance and mycelia growth speed. Ultrastructural analysis indicated that culture media containing limonene had no visible toxic activity that could promote morphological changes in the fungal cell wall. The biomass of A. niger LBM055 was distinctive in liquid media supplemented with R-(+)-limonene (0·57 ± 0·07 g) and it was selected to prove bioconversion capacity, under static and agitated conditions, and converted up to 98% of limonene, yielding a wide variety of products that were quantified by GC-FID. It was obtained at molecular weights less than limonene (64-100%), between limonene and α-terpineol (12-72%) and greater than α-terpineol (2-48%). CONCLUSIONS: Aspergillus niger LBM 055, Penicillium sp. LBM 150, Penicillium sp. LBM 151 and Penicillium sp. LBM 154 showed to the highest tolerance and growth rate in mediums supplemented with R-(+)-limonene and orange and lemon essential oils. Particularly, A. niger LBM055, showed limonene bioconversion capability and produced different molecular weights compounds such us α-terpineol. SIGNIFICANCE AND IMPACT OF THE STUDY: Different bioproducts can be obtained by changing operative condition with the same fungus, and this bioprocess aspect is a significant approach to be adopted on industrial scale leading to the creation of new natural flavours and fragrance compositions.

Effect of information about mandarin internal maturity on consumer hedonic and sensory expectations: a cross-cultural study in Spain and Mexico.

BACKGROUND: Under certain climate conditions, citrus fruit may reach optimum internal maturity while the rind is still green. It is therefore customary to enhance skin colour changes by submitting early citrus varieties to ethylene degreening treatment, which implies a cost and may result in external disorders. In this study, the effect on consumer expectations (sensory and hedonic) of providing them with information about the internal maturity of non-degreened mandarins (greenish-coloured rind) was evaluated. RESULTS: Mandarins with three different external colour indices (CI), CI = -6, CI = +1 and CI = +5, and three ways of conveying information, were investigated: (i) No information (NoInfo), (ii) The text 'Mandarins ready to eat' (Text) and (iii) Text + Visualisation of mandarin flesh (orange-coloured in all cases) (Text+Flesh). Consumer expected liking, purchase intention and sensory expectations were markedly affected after receiving the different information types. The greatest effect was detected when Text+Flesh information was provided. Rind mandarin colour was also a determinant factor of how consumer expectations were modified by the received information. Moreover, our results revealed some differences among Spanish and Mexican consumers, since maturity information had a stronger effect on hedonic expectations of Mexican consumers. CONCLUSIONS: When mandarins reach CI = +5 (pale orange-coloured rind with small areas still green), letting consumers know that mandarins are ready to eat by means of Text+Flesh information may be a non-cost strategy to avoid degreening treatment or to shorten its length. © 2021 Society of Chemical Industry.

Economic threshold for Tetranychus urticae (Acari: Tetranychidae) in clementine mandarins Citrus clementina.

Tetranychus urticae is a key pest of citrus in Spain, especially of clementine mandarin trees. The effects of this mite on fruit production were assessed in 24 clementine trees for three consecutive years. Trees were visited weekly and spider mite and phytoseiid mite populations and leaf flush patterns were estimated. At the end of the season, mandarins were harvested, weighed, and mite damage (scarring on the fruit) characterized. Negative relationships between spider mite density and yield (kg/tree) and fruit damage (% scarred fruit rind) were found. The multivariate regressions highlighted the key role of phytoseiid mites and leaf flush patterns, which were negatively related to fruit damage. The shortest sampling period that satisfactorily predicted fruit damage at harvest, extended from August to mid-October. For IPM purposes, an action threshold of 31.1 mites m⁻² of symptomatic leaf was estimated. Taking into account spider mite dynamics, the economic threshold ranged from 10 to 15 mites m⁻² of symptomatic leaf. When this threshold is exceeded growers would have a 1-week window to apply the control technologies against T. urticae of their choice.

Citrus medica: nutritional, phytochemical composition and health benefits - a review.

Citrus medica (Citron) is an underutilized fruit plant having various bioactive components in all parts of the plant. The major bioactive compounds present are iso-limonene, citral, limonene, phenolics, flavonones, vitamin C, pectin, linalool, decanal, and nonanal, accounting for several health benefits. Pectin and heteropolysachharides also play a major role as dietary fibers. The potential impact of citron and its bioactive components to prevent or reverse destructive deregulated processes responsible for certain diseases has attracted different researchers' attention. The fruit has numerous nutraceutical benefits, proven by pharmacological studies; for example, anti-catarrhal, capillary protector, anti-hypertensive, diuretic, antibacterial, antifungal, anthelmintic, antimicrobial, analgesic, strong antioxidant, anticancerous, antidiabetic, estrogenic, antiulcer, cardioprotective, and antihyperglycemic. The present review explores new insights into the benefits of citron in various body parts. Throughout the world, citron has been used in making carbonated drinks, alcoholic beverages, syrup, candied peels, jams, marmalade, cordials, and many other value added products, which suggests it is an appropriate raw material to develop healthy processed food. In the present review, the fruit taxonomical classification, beneficial phytochemicals, antioxidant activities, and health benefits are discussed.

Vector control and foliar nutrition to maintain economic sustainability of bearing citrus in Florida groves affected by huanglongbing.

BACKGROUND: Huanglongbing (HLB) or citrus greening is a bacterial disease vectored by the Asian citrus psyllid (ACP) causing tree decline, and yield loss. Vector control and foliar nutrition are used in Florida to slow the spread of HLB and mitigate debilitating effects of the disease. A four year replicated field study was initiated February 2008 in a 5.2-ha commercial block of young 'Valencia' orange trees employing a factorial design to evaluate individual and compound effects of vector management and foliar nutrition. Insecticides were sprayed during tree dormancy and when psyllid populations exceeded a nominal threshold. A mixture consisting primarily of micro- and macro-nutrients was applied three times a year corresponding to the principal foliar flushes. RESULTS: Differences in ACP numbers from five- to 13-fold were maintained in insecticide treated and untreated plots. Incidence of HLB estimated by polymerase chain reaction (PCR), rose from 30% at the beginning of the study to 95% in only 18 months. Highest yields all four years were seen from trees receiving both foliar nutrition and vector control. Production for these trees in the fourth year was close to the pre-HLB regional average for 10 year old 'Valencia' on 'Swingle'. Nevertheless, at current juice prices, the extra revenue generated from the combined insecticide and nutritional treatment did not cover the added treatment costs. CONCLUSIONS: This experiment demonstrated that vector control, especially when combined with enhanced foliar nutrition, could significantly increase yields in a citrus orchard with high incidence of HLB. Economic thresholds for both insecticide and nutrient applications are needed under different market and environmental conditions.

Process design and economic analysis of a citrus waste biorefinery with biofuels and limonene as products.

Process design and economic analysis of a biorefinery for the treatment of citrus wastes (CW) at different capacities was carried out. The CW is hydrolyzed using dilute sulfuric acid and then further processed to produce limonene, ethanol and biogas. The total cost of ethanol for base case process with 100,000 tons/year CW capacity was calculated as 0.91 USD/L, assuming 10 USD/ton handling and transportation cost of CW to the plant. However, this price is sensitive to the plant capacity. With constant price of methane and limonene, changing the plant capacity from 25,000 to 400,000 tons CW per year results in reducing ethanol costs from 2.55 to 0.46 USD/L in an economically feasible process. In addition, the ethanol production cost is sensitive to the transportation cost of CW. Increasing this cost from 10 to 30 USD/ton for the base case results in increasing the ethanol costs from 0.91 to 1.42 USD/L.

Perfil industrial e de mercado para suco de abacaxi / Industrial outline and market for pineapple juice

Analisando o perfil das exportaçöes brasileiras, verifica-se, nos últimos 15 anos, uma tendência para serem exportadas frutas na forma processada devido principalmente à menor exigência quanto à matéria-prima, facilidade de transporte e conservaçäo. Um grande potencial tem-se apresentado para os sucos. Em virtude da ausência de uma política agressiva no mercado externo, o Brasil constitui o maior consumidor de sucos tropicais. A qualidade do suco, falta de competitividade e preço, elevados custos dos fretes, pequena escala de produçäo e elevados custos da embalagem säo os principais entraves relacionados com o abacaxi processado no mercado externo. O perfil industrial de obtençäo de sucos concentrados e simples estima um investimento de US$4,4 milhöes e um gasto com equipamentos na ordem de US$2,8 milhöes para a produçäo de 30.975t anuais de sucos. Para evitar a ociosidade na fábrica pressupôs-se a industrializaçäo