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One way to add value to tropical fruit and increase its availability in the global market is to develop new, less perishable, products from fresh fruit. The purpose of this study is to compare the perception of key quality attributes and preferences of dried mango between consumers with different familiarity and health consciousness. This study surveyed respondents from China, Indonesia, and the Netherlands via an adaptive choice‐based conjoint method (n = 483) to evaluate intrinsic quality attributes that influenced consumer preference for dried mango. Consumers in different countries have different texture, taste, and color preferences for dried mango. The most important attribute for the Dutch and Chinese was “free from extra ingredients”, while for Indonesians, it was the texture. Familiarity with dried mango and health consciousness do not influence consumer preference of intrinsic attributes of dried mango. Different preferences of intrinsic attributes of dried mango between countries are related to cultural differences. This study provides useful insights for food manufacturers into the significance of key intrinsic quality attributes in developing dried mango. Practical Application Intrinsic quality parameters of dried mango are not perceived in the same way by every consumer and this is related to cultural differences. Crispy texture is important only for Indonesian consumers, while “free from extra ingredients” is the most important for Dutch and Chinese consumers. This information is relevant when developing dried mango products for the respective markets.

The inhibitory effect of tea polyphenols on starch digestibility can contribute to the control of the glycaemic index of starchy food. In this study, wheat bread and gluten-free bread were co-digested in vitro with different amounts of tea polyphenols. The kinetics of starch digestion and polyphenol bio-accessibility during in vitro digestion were monitored. The results showed that co-digestion of bread with tea polyphenols dose-dependently slowed the starch digestion kinetics and this effect is influenced by the types of polyphenols and the presence of gluten. The presence of gluten lowered the inhibitory efficacy of tannins on starch digestibility to 7.4% and 47.5% when 25 mg of tannins were co-digested with wheat bread and gluten-free bread, respectively. In contrast, the presence of gluten had little impact on the inhibitory efficacy of monomeric polyphenols. This study shows that the release of tea polyphenols in the digestive environment is a promising strategy for controlling the glycaemic index of starchy food and that monomeric and polymeric tea polyphenols differently affect starch digestion according to the presence of gluten.

PurposeAdolescence is a period in which autonomy grows and where children develop into independent and active consumers and a period in which their food choices are also becoming more autonomous. Snacking is known to increase during the period of adolescence and the snack choice of adolescents is often unhealthy. Therefore, the purpose of this study is to know when adolescents perceive a snack as healthy. As healthiness perception could be linked to the perception of naturalness and sustainability of a snack, these are interesting product characteristics to study as well.Design/methodology/approachSemi-structured interviews with 20 adolescents were conducted to characterize their perception of healthiness, naturalness and sustainability. Chocolate snack bars were used as a stimulus product.FindingsAll participants mentioned consuming snacks because they like them. Healthiness was seen as important but was not always a priority in adolescents' snack choices. Naturalness and sustainability were concepts which the adolescents were not aware of or did not perceive as important during snack choice. The adolescents mentioned experiencing natural products to be healthier compared to not natural products. The consequences of the discerned dimensions time, impact and effect of choices were rather limited for this target group.Originality/valueUnderstanding the healthiness, naturalness and sustainability perception of chocolate snack bars by adolescents may help to better understand drivers for adolescents' snack choices.

Color is a main factor in the perception of food product quality. Food surfaces are often not homogenous at micro-, meso-, and macroscopic scales. This matrix can include a variety of colors that are subject to changes during food processing. These different colors can be analyzed to provides more information than the average color. The objective of this study was to compare color analysis techniques on their ability to differentiate samples, quantify heterogeneity, and flexibility. The included techniques are sensory testing, Hunterlab colorimeter, a commercial CVS (IRIS-Alphasoft), and the custom made CVS (Canon-CVS) in analyzing nine different vacuum fried fruits. Sensory testing was a straightforward method and able to describe color heterogeneity. However, the subjectivity of the panelist is a limitation. Hunterlab was easy and accurate to measure homogeneous samples with high differentiation, without the color distribution information. IRIS-Alphasoft was quick and easy for color distribution analysis, however the closed system is the limit. The Canon-CVS protocol was able to assess the color heterogeneity, able to discriminate samples and flexible. As a take home massage, objective color distribution analysis has a potential to unlock the limitation of traditional color analysis by providing more detailed color distribution information which is important with respect to overall product quality.

Citrus juice is widely consumed due to its high nutritional values, desirable taste, and color. The juice color is the key indicator for quality attributes affecting the consumer’s attention. Conventional thermal treatment is the common method in juice processing which adversely affects its nutritional value and appearance. Measuring the color properties of the juice is an intelligent way to control the juice quality and estimating the alteration in chemicals. In this study, the effects of different treatments on the color aspects of citrus juice including L*, a* & b* values, browning index, total color difference, chroma, and hue index were reviewed. New thermal methods such as microwave, ohmic heating, and infrared radiation are used which result in the shortened process come up time (CUT). In addition, non-thermal treatments such as pulsed electric fields, high-pressure processing, high-pressure carbon dioxide, sonication, and ultraviolet are applied to process the juice, which results in better preservation of the nutritional values. These methods are less effective in the inactivation of the enzymes playing a key role in the juices stability. Therefore, a combination of thermal and non-thermal methods is suggested to increase the effectiveness of the process as well as preserving the juice quality.

Inhibition of maltase, sucrase, isomaltase and glucoamylase activity by acarbose, epigallocatechin gallate, epicatechin gallate and four polyphenol-rich tea extract from white, green, oolong, black tea, were investigated by using rat intestinal enzymes and human Caco-2 cells. Regarding rat intestinal enzyme mixture, all four tea extracts were very effective in inhibiting maltase and glucoamylase activity, but only white tea extract inhibited sucrase and isomaltase activity and the inhibition was limited. Mixed-type inhibition on rat maltase activity was observed. Tea extracts in combination with acarbose, produced a synergistic inhibitory effect on rat maltase activity. Caco-2 cells experiments were conducted in Transwells. Green tea extract and epigallocatechin gallate show dose-dependent inhibition on human sucrase activity, but no inhibition on rat sucrase activity. The opposite was observed on maltase activity. The results highlighted the different response in the two investigated model systems and show that tea polyphenols are good inhibitors for α-glucosidase activity.

Background: Heritage food has gained attention and recognition by locals as a cultural identity and by tourists as a new food experience. Two important intrinsic quality attributes of heritage food encompass safety and authenticity. As heritage food dishes are prepared in foodservice establishment, it entails requirements on ensuring safety and authenticity of heritage food. Scope and approach: The study aims to conceptualise heritage food and identify risk factors that may compromise safety and authenticity. A semi-structured literature review was conducted to explain the heritage dimensions and to evaluate multiple food concepts relating to heritage to define the heritage food concept. Furthermore, risk factors were inferred from the literature that could compromise the safety and authenticity of heritage food. Key findings and conclusions: Three main heritage dimensions identified from literature are legacy, people and place. Based on the evaluation against the three heritage dimensions, traditional food was mostly linked to the legacy and place dimensions. Ethnic food was typically related to the dimensions people and legacy, whereas for local food the dimension place was most dominant. Literature showed that all dimensions seem to be relevant for heritage food, but the number of definitions available in the literature is still limited. Therefore, it is not yet clear if all dimensions are equally important. Furthermore, a framework was developed with the identified authenticity risk factors, which originated from literature about ethnic, local and traditional food. The identified safety risk factors are common in the foodservice sector. The framework needs to be further validated through studies with stakeholders in heritage food production.

The increasing interest in heritage food by tourists requires a deeper understanding of its concept. A previous study conceptualised heritage food into three dimensions (i.e. legacy, people and place) and developed a framework describing the main activities in heritage food production, the connection to the identified dimensions and potential authenticity risk factors. This study aims to validate the heritage food concept and the identified authenticity risk factors in the production of heritage food dishes. Semi-structured interviews with culinary professionals of foodservice establishments in Saudi Arabia and Italy were conducted to validate the concept and evaluate the risk factors based on their professional expertise. Data were analysed by thematic content analysis using MAXQDA to infer categories describing the heritage food concept. The results indicated that the previously determined heritage food dimensions were confirmed by professionals. The identified categories ‘inheritance’ and ‘authenticity of the recipe and cooking’ corresponded with legacy, whereas the category ‘locality of ingredients’ linked to place. The category ‘knowledgeable chefs representing their culture’ is related to people. Another category ‘heritage food is subject to cultural and societal influences’ emerged which demonstrates that authenticity is not static but evolves. Most culinary chefs from both countries confirmed the earlier identified authenticity risk factors. Moreover, three new authenticity risk factors arose from the interviews including ‘adaptation to customer preference’, ‘costs of ingredients’, and ‘non-native origin of chef’. Further research is necessary to investigate how these risk factors differ among various types of foodservice establishments.

Background: Food naturalness has been the subject of several recent studies and is a key trend in the food industry. There is currently no comprehensive legal definition of food naturalness, which is a multi-faceted and complex principle composed of many aspects. Naturalness-influencing aspects constituting naturalness of food ingredients are similar to those already investigated for finished food products. Scope and approach: Two research questions are posed in this review: • To what extent are the naturalness criteria for food ingredients set by ISO technical specification 19,657 “Definitions and technical criteria for food ingredients to be considered as natural” in line with the latest trends in consumer studies, reviews and reports on the topic? • What aspects contributing to naturalness of food ingredients are the most present across food ingredients’ categories? The first question is answered through a review of governmental sources and scientific literature related to food naturalness and its evaluation. The second question is addressed through four case studies. Key findings and conclusions: ISO TS 19657 evaluates food ingredients' naturalness and only partially fulfils consumers’ requests. To build up a more comprehensive evaluation system, other aspects e.g. farming practices should be taken into consideration. The case studies presented in this review paper highlighted this need for a more extended basis for naturalness evaluation of food ingredients. A gap between technical and safety need for processing and consumer perception of processing in relation to naturalness emerged.

The kinetics of mass transfer and vitamin C loss in mango during osmotic dehydration (OD) were described by mathematical models. Water loss (WL) and weight reduction (WR) was modelled by Weibull's model, soluble solid gain (SSG) was better described by Peleg's model. Vitamin C loss was described by a multiresponse model incorporating both degradation and leaching processes into the OD-solution. Effects of vacuum impregnation (VI) and pectin methylesterase (PME) addition on the model parameters were evaluated. VI increases SSG indicated by a 55% lower value of k2 in the Peleg model (P < 0.05). PME addition showed no significant effect on the mass transfer kinetics. The major mechanism of vitamin C loss during OD was degradation. The pretreatments have no significant effect on degradation and leaching rate constants of vitamin C. The combination of modelling the mass transfer and vitamin C retention was shown to be valuable in optimizing the OD process design to enhance the health-promoting value of OD mango (sugar content, vitamin C) and processing time.

The effects of pretreatment with vacuum impregnation (VI) and high pressure (HP) and adding pectin methylesterase (PME) with calcium on the quality of osmotic dehydrated mango of different ripeness were investigated. Unripe and ripe ‘Kent’ mango cubes were osmotic dehydrated (OD at 50 °C in 60 °Brix sucrose solution containing 2 g calcium lactate/100 g and 0 or 0.48 mL PME/100 g), preceded either by VI (OD-VI) or HP (OD-HP). Use of unripe mango in OD showed two to five-fold higher soluble solid gain (SSG) compared to ripe mango for all treatments. Unripe mango pretreated with OD-VI showed the lowest water loss (WL) and the highest SSG. OD-HP had a similar but less pronounced effect as OD-VI on WL and SSG. Hue (h*) were generally preserved and color intensity (C*) were maintained or only slightly increased in both ripeness in all treatments. Lightness (L*) was greatly reduced in unripe mango but stable in ripe mango. In general, firmness and work of shear slightly increased when adding PME.

Cape gooseberry is a fruit recognised for having relevant contents of health-promoting compounds. Changes in the content of phytochemicals (ascorbic acid, β-carotene, catechin and epicatechin), hydroxymethylfurfural (HMF) and antioxidant activity of this fruit were studied at various temperatures and times. Ascorbic acid degradation was described by a first order reaction. β-carotene was not degraded and followed an isomerization reaction from 80 °C onwards. Formation of HMF was described with a consecutive zero together with a first order reaction model. The contents of catechin and epicatechin increased at 40 °C. More than three competing reactions did not allow to make kinetic modelling. Antioxidant activity followed fractional first order conversion model. Comparison with kinetics found in other fruits showed that health-promoting compounds of cape gooseberry are relatively more stable to heat treatment. This makes cape gooseberry suitable for the preparation of foods (jam, juices and dehydrated fruit) with relevant health-promoting compounds contents.

Stir-frying is a cooking method, originating from Asia, in which food is fried in small amount of very hot oil. Nowadays in many other parts of the world stir-frying is a very popular method to prepare vegetables, because it is fast and fried vegetables are tasty. However, the retention of phytochemicals like the health-beneficial glucosinolates in Brassica vegetables is less explored for stir-frying in comparison to other cooking methods. This study investigates the retention of glucosinolates in Chinese cabbage (Brassica rapa ssp. pekinensis) and pakchoi (Brassica rapa ssp. chinensis) as affected by stir-frying at various cooking durations and temperatures. Stir-frying experiments were performed at set pan temperatures ranging from 160 to 250 °C for a duration of 1 to 8 min. Results showed that aliphatic glucobrassicanapin is the most abundant glucosinolate identified in fresh Chinese cabbage and pakchoi, contributing for 48 and 63% of the total glucosinolate content, respectively, followed by glucoiberin and gluconapin. Stir-frying retains the glucosinolates even at the highest temperature applied. Such retention is explained by the quick inactivation of the glucosinolate-hydrolytic enzyme myrosinase during the first minutes of frying, and by the thermal stability of the glucosinolates at those temperature/time conditions. Moreover, due to the absence of a separate water phase, leaching losses did not occur, in contrast to what is observed when boiling Brassica vegetables. These results show that stir-frying may be a suitable health-beneficial cooking option that prevents the loss of glucosinolates.

Cape gooseberry is the fruit of the plant Physalis peruviana L. and has gained commercial and scientific interest for its contents of health-promoting compounds. An integral approach to estimate shelf life of cape gooseberry was conducted taking into account physicochemical, microbiological and nutritional changes and consumer acceptance. The experiments were performed for 5 independent harvest times during two years (2014–2015). The conditions of storage were temperatures of 4, 8 and 12 °C and a relative humidity of 80%. Fruit with (Y) and without calyx (N) were packed into polyethylene terephthalate (PET) trays and polypropylene (PP) baskets, respectively. The experiment was conducted for a total of 76 d or shorter when the fruit was spoilt earlier. Fruit with the calyx showed a longer shelf life, while 8 °C was the temperature that gave longer shelf lives irrespective of the calyx presence. The critical quality attribute of shelf life without calyx was fungal growth, which determined consumer acceptance; weight loss was the most critical quality attribute for the fruit with calyx. Studying various quality attributes in an integral way appeared to give a better understanding of the shelf life.

Although the monkey orange (Strychnos spp.) tree fruit is widely distributed in Southern Africa and particularly in Zimbabwe, it is underutilized and little attention has been given to its potential commercialisation due to limited knowledge and information. Most of the fruits and their products are wasted because of limited harvest time, process control and storage conditions, leading to variability in shelf life and sensory quality, thereby impacting nutritional quality. Traditional processing techniques make insufficient use of this food resource within rural communities. This study aimed at identifying the existing bottlenecks by means of a survey among 102 smallholder farming respondents in the wet and dry regions of Zimbabwe. Results revealed that S. cocculoides and S. spinosa were used by 48% of respondents as a functional ingredient in porridge, by 25% in fermented mahewu drink and by 15% of respondents as a non-alcoholic juice. The fruits of S. innocua and S. madagascariensis are preferably processed into dried products. Taste, flavour and colour were the important quality characteristics for all processed products, and constraints to be solved are seed-flesh separation, long processing times, separation of juice and pulp during storage as well as pulp viscosity. Respondents reported monkey orange products to have health benefits for children and immune-compromised people, who, on regular consumption, have reportedly increased weight and resistance to disease. The positive perception about the processed products of Strychnos spp. offer a good opportunity to improve nutrition security by capitalizing on these not-yet-fully-exploited resources, but technological solutions to improve sensory quality and shelf life must be developed.

Key message Overexpression of BoMYB29 gene up-regulates the aliphatic glucosinolate pathway in Brassica oleracea plants increasing the production of the anti-cancer metabolite glucoraphanin, and the toxic and pungent sinigrin. Abstract Isothiocyanates, the bio-active hydrolysis products of glucosinolates, naturally produced by several Brassicaceae species, play an important role in human health and agriculture. This study aims at correlating the content of aliphatic glucosinolates to the expression of genes involved in their synthesis in Brassica oleracea, and perform functional analysis of BoMYB29 gene. To this purpose, three genotypes were used: a sprouting broccoli, a cabbage, and a wild genotype (Winspit), a high glucosinolate containing accession. Winspit showed the highest transcript level of BoMYB28, BoMYB29 and BoAOP2 genes, and BoAOP2 expression was positively correlated with that of the two MYB genes. Further analyses of the aliphatic glucosinolates also showed a positive correlation between the expression of BoAOP2 and the production of sinigrin and gluconapin in Winspit. The Winspit BoMYB29 CDS was cloned and overexpressed in Winspit and in the DH AG1012 line. Overexpressing Winspit plants produced higher quantities of alkenyl glucosinolates, such as sinigrin. Conversely, the DH AG1012 transformants showed a higher production of methylsulphinylalkyl glucosinolates, including glucoraphanin, and, despite an up-regulation of the aliphatic glucosinolate genes, no increase in alkenyl glucosinolates. The latter may be explained by the absence of a functional AOP2 gene in DH AG1012. Nevertheless, an extract of DH AG1012 lines overexpressing BoMYB29 provided a chemoprotective effect on human colon cells. This work exemplifies how the genetic diversity of B. oleracea may be used by breeders to select for higher expression of transcription factors for glucosinolate biosynthesis to improve its natural, health-promoting properties. Electronic supplementary material The online version of this article (10.1007/s11103-019-00890-2) contains supplementary material, which is available to authorized users.

This paper studied the nutritional impact of the use of juice from Strychnos cocculoides (monkey orange) in a maize-based porridge. Monkey orange juice is traditionally used to supplement maize porridge - a staple breakfast cereal especially for vulnerable groups. Monkey orange fruits contain high amounts of micronutrients and phenolic compounds and are widely distributed throughout sub-Saharan Africa. The valuable components can be efficiently extracted by traditional and pectinase maceration techniques. The bioaccessibility of minerals and main phenolic compounds in maize porridge (5 g maize meal) supplemented by monkey orange juice (100 ml) were assessed after in-vitro digestion together with the kinetics of starch degradation. Caffeic and protocatechuic acids exceeded 100%, and chlorogenic acid 81% bioaccessibility after simulated intestinal digestion. Rutin was undetected after the simulated intestinal phase due to precipitation in the pellet. In-vitro bioaccessibility of minerals ranged from 12 to 62% in monkey orange enriched porridge. A 50–70% decrease of starch hydrolysis was observed at the end of the simulated intestinal digestion of monkey orange maize porridge confirming the known potential of phenolic compounds to decrease the glycaemic index of starch-rich foods. Consequently monkey orange juice appeared a suitable ingredient to enrich staple maize porridge thanks to its micronutrients and health benefit potential. Similar relationships of other fruits and starchy foods warrant study as a means to improve the nutritional quality of the diets of malnourished populations.

BACKGROUND: Kales are often a key ingredient of traditional foods, containing high amounts of indolic glucosinolates (precursors of indole-3-carbinol and ascorbigen), carotenoids and phenolics. The present trend to associate traditional foods crops with health-promoting properties suggested to investigate the degradation kinetic of three Brassica oleracea landraces' phytochemicals subjected to boiling, steaming and stir-frying. RESULTS: Boiling led to substantial losses due to leaching. Glucosinolates followed a second-order degradation kinetic (20% of their initial values after 10min in Nero di Toscana). Phenolic content in leaves+cooking water remained unchanged, whereas their antioxidant capacity was reduced. Carotenoid content increased during the first minutes of boiling. Steaming showed the highest retention of phytochemicals, with often zero-order degradation kinetic, having however a strong effect on colour. Stir-frying produced high losses for all measured compounds; also, β-carotene reduced its content to 10-23% independently of variety. Conversion values for indole-derived compounds ranged from non-detectable to 23.5%. CONCLUSION: Variety strongly affected observed degradation rates because of a different glucosinolate composition and leaf structure. With this research, more information has been gained on the degradation kinetic of B. oleracea landraces' phytochemical compounds upon cooking, highlighting the possibility of improving bioactive component retention.

Monkey orange (Strychnos spp.) is a widely distributed fruit species in Southern Africa commonly consumed by the local population. It has potential to improve the nutritional status of rural populations, being a precious food source in areas with periodic shortages, since it is rich in vitamin C, zinc, and iron. To improve the availability of this food outside its production season, processing and preservation techniques used at household level need upgrading as they are unreliable and their effects on nutritional quality are unknown. Based on this review, we recommend better indigenous fruit production as a sustainable solution to malnutrition in rural areas in transition countries.

In this study, the effect of berry polyphenols on starch digestion was tested in vitro both by co-digestion of berry extract with bread or by fortifying bread with berry extract. Results show that the co-digestion of bread with berry extracts significantly reduce the rate and extent of starch digestion. Sixty one percent of starch digestion is inhibited by co-digesting 1 g of raspberry extract with 4 g of the bread. The inhibition obtained by co-digesting berry extracts and bread is much higher than the inhibition obtained by digesting berry-fortified bread. Interactions of polyphenols with matrix reduce polyphenols bio-accessibility, thus reducing the amount of polyphenols available for α-amylase inhibition. The interaction of polyphenols and starch seems also a crucial mechanism for the inhibition of starch digestion. This study shows that the co-ingestion of berry polyphenols with bread is a promising strategy to reduce glycaemic index of starchy food.

Moisture content plays a pivotal role in the kinetic modelling of the quality attributes during thermal processing of foods. Vacuum frying of mango chips, was chosen to demonstrate the applicability of this novel modelling approach that links a dynamic moisture model to models for changes in fat content, texture, and color. Results show that moisture loss is best described by an exponential model with an Ea of 40.0 ± 4.2 and 27.2 ± 2.3 kJ mol−1 for unripe and ripe mango respectively. The dynamic moisture content was linked to the fat content by a Gompertz model, and to the hardness by an exponential model. By using thermodynamic principles, the moisture model predicts the dynamic local product temperature that can be linked to the reaction rates of the consecutive color change reaction models. The integration of these models is a powerful tool in product and process optimization to produce high quality vacuum fried fruit products. Industrial relevance text Food moisture content changes during many thermal processing techniques but it also plays a pivotal role in changes of the quality attributes of foods. Quality change models were developed that integrate changes in the moisture content with changes in quality attributes. These models can be applied to produce a minimal fat content and low moisture content while getting a desired color change and/or to produce a specific texture characteristics. Moisture dependent models for quality changes are powerful tools for optimizing many other products and process.

Vacuum frying of fruits enables frying at lower temperatures compared to atmospheric frying, thereby improving quality attributes of the fried product, such as oil content, texture, retention of nutrients, and color. Producing high-quality vacuum-fried fruit is a challenge, especially because of the high initial water content of fruits that requires long frying times. Factors influencing vacuum-fried fruit quality attributes are the type of equipment, pre-treatments, processing conditions, fruit type, and fruit matrix. Pre-treatments such as hot air, osmotic drying, blanching, freezing, impregnation, anti-browning agents, and hydrocolloid application strongly influence the final quality attributes of the products. The vacuum-frying processing parameters, namely frying time, temperature, and vacuum pressure, have to be adjusted to the fruit characteristics. Tropical fruits have different matrix properties, including physical and chemical, which changed during ripening and influenced vacuum-fried tropical fruit quality. This paper reviews the state of the art of vacuum frying of fruit with a specific focus on the effect of fruit type and matrix on the quality attributes of the fried product.

BACKGROUND: Glucosinolates are a group of phytochemicals that are abundant in cruciferous vegetables and precursors of the potentially chemopreventive isothiocyanates. Isothiocyanates may reduce oxidative stress and inflammation, but little is known regarding the association between glucosinolate intake and risk of type 2 diabetes (T2D). OBJECTIVE: To evaluate the association between the intake of glucosinolates and the incidence of T2D in US men and women. DESIGN: This prospective cohort study investigated 200,907 women and men [71,256 women from the Nurses’ Health Study (NHS; 1984–2012), 88,293 women from the NHS II (1991–2013), and 41,358 men from the Health Professionals Follow-Up Study (1986–2012)] who were free of diabetes, cardiovascular disease, and cancer at baseline. Diet was assessed using validated semiquantitative food frequency questionnaires. Self-reported T2D incidence was confirmed by a supplementary questionnaire. RESULTS: During follow-up in the 3 cohorts, we accumulated 4,303,750 person-years and 16,567 incident cases of T2D. After adjustment for major lifestyle and dietary risk factors for T2D, participants in the highest quintile of total glucosinolate intake had a 19% higher risk (95% CI: 13%, 25%; P(trend)

Chewing disrupts broccoli cells, and myrosinase can effectively hydrolyze the glucosinolate glucoraphanin into the biological active sulforaphane. The influence of chewing time and steaming time on glucoraphanin hydrolysis as well as sulforaphane and sulforaphane nitrile formation in broccoli was studied. To study the effect of chewing time on differently steamed broccoli, broccoli was chewed for 11 s, 22 s, 30 s and 40 s by volunteers. To determine the effect of steaming time, raw and steamed broccoli samples were chewed for 22 s. Glucoraphanin, sulforaphane and sulforaphane nitrile were analyzed in all samples. Longer chewing times of raw, 0.5-min and 1-min steamed broccoli, which contained active myrosinase, lead to a higher hydrolysis. The highest hydrolysis rate of glucoraphanin was found in 0.5-min steamed broccoli (38%) and 2-min steamed samples which contained the highest sulforaphane concentration. This could lead to a recommendation to steam broccoli for a short time before consumption.

cope Optimization of bioavailability of dietary bioactive health-beneficial compounds is as important as increasing their concentration in foods. The aim of this study was to explore the change in bioavailability of isothiocyanates in broccoli sprouts incorporated in protein, fibre and lipid gels. Methods and results Five participants took part in a cross-over study and collected timed urine samples before up to 24-hours after consumption of proteins, dietary fibres and lipids gels containing broccoli spouts powder. Sulforaphane and iberin metabolites were determined in the urine samples. Samples in which sulforaphane and iberin were pre-formed by myrosinase, led to a higher bioavailability of those compounds. Compared to the control broccoli sprout, incorporation of sprouts in gels led to lower bioavailability for pre-formed sulforaphane and iberin (although for sulforaphane the lower bioavailability was not significantly different) whereas, for the gels rich in their precursors, glucoraphanin and glucoiberin, the opposite trend was observed (although not significantly different). Conclusion This explorative study suggests that isothiocyanates bioavailability can be modulated by food structure and composition and further and deeper investigations are needed to develop food products that lead to an optimized isothiocyanates bioavailability. This article is protected by copyright. All rights reserved

Tomato fractions were subjected to pulsed electric fields treatment combined or not with heating. Results showed that pulsed electric fields and heating applied in combination or individually induced permeabilization of cell membranes in the tomato fractions. However, no changes in β-carotene and lycopene bioaccessibility were found upon combined and individual pulsed electric fields and heating, except in the following cases: (i) in tissue, a significant decrease in lycopene bioaccessibility upon combined pulsed electric fields and heating and heating only was observed; (ii) in chromoplasts, both β-carotene and lycopene bioaccessibility significantly decreased upon combined pulsed electric fields and heating and pulsed electric fields only. The reduction in carotenoids bioaccessibility was attributed to modification in chromoplasts membrane and carotenoids-protein complexes. Differences in the effects of pulsed electric fields on bioaccessibility among different tomato fractions were related to tomato structure complexity.

The formation of health‐beneficial isothiocyanates (ITCs) from glucosinolates depends on a wide variety of plant‐intrinsic factors (e.g., concentration of glucosinolates, activity of myrosinase, and specifier proteins) and on a multitude of extrinsic postharvest factors such as the conditions used during industrial processing, domestic preparation, mastication, and digestion. All of these factors contribute to a large variability in the formation of ITCs (and other breakdown products), as well as their intake and absorption upon consumption of Brassica vegetables. This uncertainty in ITC intake and absorption is a barrier for the determination of an optimal Brassica vegetable consumption pattern. In this review, the intrinsic and extrinsic factors that affect the formation, intake, and absorption of ITCs are described according to the most recent findings. The focus of this review includes the hydrolysis reaction mechanisms, the elucidation of the primary factors that play a role in the hydrolysis reaction, the influence of processing and cooking conditions, the effect of chewing, and the roles of the gastric and upper intestinal phases, including the effect of the meal composition (e.g., the effect of other meal compounds present during digestion) on the potential formation of ITCs.

Aims: This study explores the biofumigation effects of glucosinolate (GSL) containing Brassica oleracea plant material on beneficial, non-target soil organisms, and aims to relate those effects to differences in GSL profiles. Methods: Leaf material of purple sprouting broccoli 'Santee', Savoy cabbage 'Wintessa', and the wild B. oleracea accession Winspit was analysed for GSL production and used for biofumigation experiments on the beneficial soil invertebrates, Folsomia candida (springtail) and Eisenia andrei (earthworm) and the soil bacterial community. Results: When mixed into soil, the Winspit plant material exerted the highest toxic effects on beneficial soil invertebrates by reducing survival and reproduction. Total GSL levels varied substantially between genotypes, in particular the aliphatic GSL (AGSL) sinigrin and gluconapin being highly abundant or exclusively present in Winspit. Differences between the genotypes regarding biofumigation effects on the soil microbial community were only observed on a temporal basis with the largest difference in bacterial community structure after 1 week. Conclusions: The high total GSL content in biofumigated soil could explain the toxicity of Winspit for soil invertebrates. These effects are likely to be the results of high AGSL levels in Winspit. The use of wild B. oleracea crops, such as Winspit, for biofumigation practices would need a proper assessment of the overall impact on soil biota before being applied on a wide scale.

The healthiness of a vegetable cannot solely be inferred from the amount of health-promoting compounds in the raw materials. Brassica vegetables, for example, are consumed mostly after processing to improve palatability and to extend the shelf life. However, processing also results to various changes in the content of glucosinolates which intakes are associated with a reduced risk of several cancers. The large variety in cooking practices and processing methods affect the glucosinolate content in the vegetables, particularly due to processes that allow for enzymatic hydrolysis and thermal degradation of glucosinolates, and leaching of the bioactive components. Knowledge on the effect of preparation and processing of Brassica vegetables is important to evaluate the healthiness of the consumed product and to investigate mechanisms to retain high glucosinolate levels at the stage of consumption and to increase the intake of health-protective compounds by the consumer. By using a mechanistic approach, the fate of glucosinolates during different processing and preparation methods and conditions can be explained. Boiling and blanching reduce the glucosinolate content significantly particularly because of the mechanisms of leaching following cell lysis and diffusion, and partly due to thermal and enzymatic degradation. Steaming, microwave processing, and stir frying either retain or only slightly reduce the glucosinolate content due to low degrees of leaching. These methods can enhance the accessibility of glucosinolates from the plant tissue. Fermentation reduces the glucosinolate content considerably, the underlying mechanisms are not yet completely clear, but enzymatic breakdown seems to play an important role. Studying the changes of glucosinolates during processing by a mechanistic approach is shown to be valuable to redesign the processing and to reformulate the product for improving health benefits of these compounds.

Consumption of glucosinolate-rich Brassicales vegetables is associated with a decreased risk of cancer with enzymatic hydrolysis of glucosinolates playing a key role. However, formation of health-promoting isothiocyanates is inhibited by the epithiospecifier protein in favour of nitriles and epithionitriles. Domestic processing conditions, such as changes in pH value, temperature or dilution, might also affect isothiocyanate formation. Therefore, the influences of these three factors were evaluated in accessions of Brassica rapa, Brassica oleracea, and Arabidopsis thaliana. Mathematical modelling was performed to determine optimal isothiocyanate formation conditions and to obtain knowledge on the kinetics of the reactions. At 22 °C and endogenous plant pH, nearly all investigated plants formed nitriles and epithionitriles instead of health-promoting isothiocyanates. Response surface models, however, clearly demonstrated that upon change in pH to domestic acidic (pH 4) or basic pH values (pH 8), isothiocyanate formation considerably increases. While temperature also affects this process, the pH value has the greatest impact. Further, a kinetic model showed that isothiocyanate formation strongly increases due to dilution. Finally, the results show that isothiocyanate intake can be strongly increased by optimizing the conditions of preparation of Brassicales vegetables.

Fermentation can reduce the concentration of health-promoting glucosinolates in Brassica vegetables. The endogenous enzyme myrosinase is hypothesised to mainly responsible for the degradation of glucosinolates during fermentation. In order to retain glucosinolates in the final fermented product, the role of myrosinase activity during the production of sayur asin was investigated. Sayur asin is a traditionally fermented product of Indian mustard (Brassica juncea) commonly consumed in Indonesia. It is prepared by a spontaneous fermentation of withered (sun-dried) B. juncea leaves. The leaves of B. juncea contain a substantial amount of the aliphatic glucosinolate sinigrin. Three withering methods were investigated to obtain B. juncea leaves with different myrosinase activities prior to fermentation. Results show that withering by oven at 35 °C for 2.5 h and by microwave at 180 W for 4.5 min reduced myrosinase activity by 84 and 74 %, respectively. Subsequently, sinigrin was not detectable in the leaves after 24 h of incubation in the fermentation medium. However, withering by microwave for 2 min at 900 W inactivated myrosinase completely and produced sayur asin with a sinigrin concentration of 11.4 µmol/10 g dry matter after 7 days of fermentation. This high power-short time pretreatment of B. juncea leaves contributes to the production of sayur asin containing significant levels of health-promoting glucosinolate. In this study, the effect of myrosinase activity during Brassica fermentation was quantified, and optimised production methods were investigated to retain glucosinolate in the final product.

Glucosinolates (GLSs), health promoting compounds commonly found in Brassica vegetables, were studied during sayur asin fermentation made from Indian mustard (B. juncea). The current preliminary study aims to investigate the changes of glucosinolates content during 3 and 7 days of fermentation in two different media, i.e. coconut water and tajin liquor, and salt concentrations of 2.5 and 10%. The glucosinolates were analysed by HPLC after sample extraction in hot methanol followed by purification and de-sulphation. Results show that sinigrin was the most dominant glucosinolate among others, i.e. gluconapin, glucobrassicin, 4-hydroxy-glucobrassicin, 4-methoxy-glucobrassicin, and neo glucobrassicin, accounting for about 1000 and 4000 µmol/10 g dw in raw Indian mustard. Unfortunately, fermentation has substantially reduced the glucosinolates content in sayur asin. After 3 days of fermentation the sinigrin content was reduced by 95% as compared to that in the raw vegetable. The indole GLSs 4-methoxy-glucobrassicin and neo-glucobrassicin concentration decreased to 80-90% of the fresh materials. However, the decreasing mechanisms as well as factors contributing to the decrease of the glucosinolates could not be explained yet.

BACKGROUND: Kales are often a key ingredient of traditional foods, containing high amounts of indolic glucosinolates (precursors of indole-3-carbinol and ascorbigen), carotenoids and phenolics. The present trend to associate traditional foods crops with health-promoting properties suggested to investigate the degradation kinetic of three Brassica oleracea landraces' phytochemicals subjected to boiling, steaming and stir-frying. RESULTS: Boiling led to substantial losses due to leaching. Glucosinolates followed a second-order degradation kinetic (20% of their initial values after 10 min in Nero di Toscana). Phenolic content in leaves + cooking water remained unchanged, whereas their antioxidant capacity was reduced. Carotenoid content increased during the first minutes of boiling. Steaming showed the highest retention of phytochemicals, with often zero-order degradation kinetic, having however a strong effect on colour. Stir-frying produced high losses for all measured compounds; also, β-carotene reduced its content to 10–23% independently of variety. Conversion values for indole-derived compounds ranged from non-detectable to 23.5%. CONCLUSION: Variety strongly affected observed degradation rates because of a different glucosinolate composition and leaf structure. With this research, more information has been gained on the degradation kinetic of B. oleracea landraces' phytochemical compounds upon cooking, highlighting the possibility of improving bioactive component retention. © 2016 Society of Chemical Industry.

Steaming has been reported to better retain the glucosinolate (GS) content in Brassica vegetables than boiling. However, there is little information on the GS content, colour, and texture attributes in Brassica vegetables in relation to the duration of steaming. This study investigated the effect of the duration of steaming, which was applied in certain commercial preparation processes, on the GS content, colour, and texture of white cabbage. Results showed that the total accessible content of GSs increases initially during steaming until 10 min followed by a consistent decline up to 180 min. This observed initial increase is mainly due to the content of aliphatic GSs rather than indole GSs, which tend to decrease from the start of steaming. A mathematic model for the observed behaviour of the GSs, taking into account several mechanisms, is proposed and fitted to the data. The intensity of the green colour of the cabbage slightly increased during the first 15 min of steaming followed by a decrease onwards. The hardness showed a continuous decline during the entire steaming duration. The study indicates that steaming up to 10 min could promote the health properties as well as the colour and texture attributes of steamed cabbage.

The kinetics of the thermal degradation of vitamin C of marula, mango and guava pulp at different heat treatments at temperature ranging from 80 to 150 °C were investigated. For temperatures lower than 125 °C, the ascorbic acid in marula pulp was about 15 fold more stable to heat than the ascorbic acid in mango and guava pulp. The results showed that a simple first order degradation model could not describe the vitamin C degradation as biphasic behaviour was observed. Therefore the model was transformed in a two-fraction model in which the vitamin C content is divided in relatively stable and instable fractions. Marula had a low kd1,100°C of 7.2 × 10−3 min−1 compared to kd1,100°C of 1.2 × 10−1 min−1 for guava and 1.3 × 10−1 min−1 for mango. Guava had the highest activation energy, Ea of 58 kJ/mol, followed by mango with 39 kJ/mol and then marula with 29 kJ/mol.

Glucosinolate (GL) stability has been widely studied in different Brassica species. However, the matrix effect determined by the presence of other ingredients occurred in many broccoli-based traditional recipes may affect GL thermal degradation. In this study, the matrix effect on GL thermal degradation was investigated by means of binary systems containing broccoli and another ingredient such as potato, corn starch, lentils protein or onion. Data showed that in binary systems the GL degradation was lower compared to the only-broccoli system, in particular in the broccoli/onion systems. The kinetics of GL degradation in broccoli/onion systems at different ratios showed that the higher the amount of onion, the higher the protective effect and that GL thermal degradation followed a second order model. Finally the possibility that the effect was related to the amount of flavonoids present in onions was ruled out by data obtained using broccoli/onion systems made with three onion varieties having different flavonoid content. This study shows for the first time that the presence of other food ingredients can efficiently reduce GL thermal degradation. The protective effect of onion, often present in the traditional recipes of broccoli soups in many countries, points out that the interaction of different ingredients may not only improve the taste of a dish, but also the healthiness.

The aim of this study was to investigate the chemopreventive effects of widely consumed cruciferous vegetables, namely Brussels sprouts and red cabbage towards 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-induced preneoplastic lesions [liver glutathione-S-transferase placental positive (GST-P(+)) foci and colonic aberrant crypt foci (ACF)]. Male F344 rats were treated with IQ (100 mg/kg bw/g) on 10 alternating days and received drinking water supplemented with Brussels sprouts and red cabbage juices (5% v/v) before and during the carcinogen treatment. From each vegetable two different cultivars were tested. Brussels sprouts reduced the frequency of IQ-induced aberrant foci in both organs (41-52% in the colon and 27-67% in the liver). Also, Brussels sprouts drastically diminished (85-91%) the size of liver GST-P(+) foci, but no such effect was seen in the colon. With red cabbage, the size of liver GST-P(+) foci was markedly reduced (41-83%) whereas the foci frequency was only moderately decreased (19-50%). No protection was seen in the colon after treatment with red cabbage. Cooking (10 min, 100 degrees C) of the vegetables had no influence on their protective effects. The stronger chemoprotective effects of Brussels sprouts may be due to the fact that the overall glucosinolate contents were substantially (2-3-fold) higher than those of the cabbage cultivars, but it was not possible to attribute the reduction of preneoplastic lesions to specific glucosinolates. The activities of hepatic UDP-glucuronosyltransferase form 2 (UDPGT-2) and cytochrome P4501A2 were increased by both vegetables. The induction effect of Brussels sprouts on the activity of UDPGT-2 was more marked than that of the red cabbage cultivars, suggesting that increased glucuronidation of IQ may account for the reduction of the preneoplastic lesions. Our findings support the assumption that Brassica vegetables protect against the carcinogenic effects of heterocyclic amines.

This work concerns the degradation of the nutritional compounds glucoraphanin (GR) and vitamin C (Vc), and the inactivation of the enzyme myrosinase (MYR) in broccoli ( Brassica oleracea var. italica ) during drying with air temperatures in the range of 30–60 °C. Dynamic optimization is applied to find the optimized temperature trajectories that minimize degradation and inactivation. Simulation and experimental results for optimized temperature trajectories are compared to constant inlet air temperature drying at 40 and 50 °C. The results show that with the optimized temperature trajectories the retention of GR, MYR and Vc improved significantly. Moreover, the experiments show that degradation and inactivation during drying is slower than expected from kinetic studies. The deviation is explained from the difference in the physical state of the samples used in the drying experiments, i.e. original plant tissue versus the grounded state of the plant tissue used in the experiments for the kinetic studies. The results indicate that besides temperature and moisture content the physical state is also an important aspect in the degradation of nutritional compounds and enzymes.

This paper presents the effects of fermentation on the retention of vitamin C, total polyphenols and antioxidant activity in the naturally fermented marula juice. The fermentation conditions have been varied: temperature ranged between 20 and 40 °C and fermentation time from 1 to 8 days. Marula juice fermented at higher temperatures ranged between 30 and 40 °C for 6 to 4 days retained high antioxidant activities, and they were positively correlated to its ascorbic acid and phenolic content. The values obtained ranged between 0.0239 ± 0.0051 and 0.029 ± 0.0038 μmol/mg for Trolox Equivalence Antioxidant Capacity, 870 ± 80 and 960 ± 130 mg/100 ml for total phenolic content and 90 ± 6 and 159 ± 15 mg/100 ml for ascorbic acid. Overall, fermented marula juice can be used as a good source for natural antioxidants.

An F2 of an interspecific cross between cultivated tomato (Lycopersicon esculentum cv. Moneymaker) and L. hirsutum f. glabratum was used to generate an RFLP linkage map. Distortion of single locus segregation (1:2:1) was observed for a number of markers from different chromosomes, always with a prevalence for L. hirsutum f. glabratum alleles. To identify quantitative trait loci (QTLs) for greenhouse whitefly (Trialeurodes vaporariorum) resistance in this F2 population, life history components of the greenhouse whitefly population were evaluated. Two QTLs affecting oviposition rate mapped to chromosome 1 (Tv-1) and 12 (Tv-2). F3 lines homozygous for either the L. esculentum allele or the L. hirsutum f. glabratum allele at one or both loci confirmed the effects of Tv-1 and Tv-2. The F2 population was also evaluated for segregation of type IV and type VI glandular trichome densities. Two QTLs affecting trichome type IV density (TriIV-1 and TriIV-2) and one affecting type VI trichome density (TriVI-1) mapped to chromosomes 5, 9 and 1, respectively. These results do not support the hypothesis that the density of type IV trichomes is involved in whitefly resistance.