‘Insects as Food and Feed: If You Can’t Beat Them,Eat Them!’—To the Magnificent Seven and Beyond

The objective of this special issue is to highlight the current state of research in the field of insects as food and feed, but also other aspects on the exploitation of insect farming. In this editorial, we make a short introduction of the topic of the special issue, briefly present the contributions that are collected in it and offer some thoughts on the future research priorities and challenges that should be addressed. Regarding insect farming, there are additional applications, such as fertilizer, health-promoting products, and cosmetics, that can be produced and utilized, that go far beyond food and feed production.     

Foliar Application of Manganese Increases Seed Yield and Improves Seed Quality of Cotton Grown on Calcareous Soils

Cotton (Gossypium hirsutum L.) is often grown on calcareous soils where manganese (Mn) deficiency is quite common. Despite the fact that Mn deficiency can limit cotton productivity the effect of foliar application of Mn was not determined. A field study was conducted to determine if foliar Mn applications during anthesis affects the growth and yield of cotton. Manganese increased the chlorophyll content by up to 17% compared with the control treatment with no difference between the two rates of Mn. Moreover, Mn increased the seed yield by an average of 30%, the number of bolls per plant by 31%, the number of bolls per square meter by 31% and boll retention by 37% compared with the control, but it did not affect the mean boll weight and the quality of the fibers. Foliar application of Mn increased seed germination by an average of 14% and increased seed vigor (AA) by an average of 28% compared with the control treatment. The results obtained here suggest that foliar Mn application can improve the lint and seed yield and also the seed quality of cotton grown for seed production on calcareous soils.     

A Study of Glycemic Response to Corinthian Raisins in Healthy Subjects and in Type 2 Diabetes Mellitus Patients

This study was designed to evaluate the metabolic response to Corinthian raisins in healthy and in patients with type 2 diabetes mellitus. Healthy subjects (n?=?15) and diabetic patients (n?=?15) received 74 g raisins or 50 g glucose as reference food. Blood samples were collected at time 0 (before the consumption) and 30, 60, 90, 120, 150 and 180 min after raisin or glucose consumption. There was no significant difference in baseline glucose and insulin between raisins and reference in both groups. The difference at glucose peaks between raisins and reference was significant in healthy and in diabetics. Glycemic and insulinemic responses were decreased after raisin consumption compared to reference. An estimate of the glycemic index would be 66.3?±?3.4.     

Diet Supplementation with Fish-Derived Extracts Suppresses Diabetes and Modulates Intestinal Microbiome in a Murine Model of Diet-Induced Obesity

Metabolic syndrome-related diseases affect millions of people worldwide. It is well established that changes in nutritional habits and lifestyle can improve or prevent metabolic-related pathologies such as type-2 diabetes and obesity. Previous reports have shown that nutritional supplements have the capacity to limit glucose intolerance and suppress diabetes development. In this study, we investigated the effect of dietary supplementation with fish-derived extracts on obesity and type 2 diabetes and their impact on gut microbial composition. We showed that nutritional supplements containing Fish Complex (FC), Fish Complex combined with Cod Powder (FC + CP), or Cod Powder combined with Collagen (CP + C) improved glucose intolerance, independent of abdominal fat accumulation, in a mouse model of diet-induced obesity and type 2 diabetes. In addition, collagen-containing supplements distinctly modulate the gut microbiome in high-fat induced obesity in mice. Our results suggest that fish-derived supplements suppress diet-induced type 2 diabetes, which may be partly mediated through changes in the gut microbiome. Thus, fish-derived supplements and particularly the ones containing fish collagen have potential beneficial properties as dietary supplements in managing type 2 diabetes and metabolic syndrome via modulation of the gut microbiome.     

Agronomic Assessment of Nitrogen Use Efficiency in Spring Wheat and Interrelations with Leaf Greenness Under Field Conditions

Four spring wheat genotypes (Triticum aestivum L.) were grown without (N0 = 0 kg N ha^?1) and under ample (N1 = 250 kg ha^?1) nitrogen (N) fertilizer in field experiments in two seasons. The aim was to assess genotypic variation in N use efficiency (NUE) components and N-related indices during grain filling thus to identify superior wheat genotypes. Leaf chlorophyll (SPAD) readings at crucial growth stages were employed to help differentiate genotypes. Interrelations between yield and N-related indices with SPAD, where also assessed to explain possible pathways of improving NUE early in the growing season. Results showed that genotypic effects on NUE were mostly evident in 2000, a year with drier preanthesis and wetter postanthesis than the normal periods. ‘Toronit’ almost always had the highest biomass yield (BY) and grain yield (GY). Except in 1999 under N0, ‘L94491? showed the highest % grain N concentration (GNC). Genotypes affected SPAD at almost all stages and N fertilization delayed leaf senescence for all genotypes and growth seasons. Correlations between SPAD at different growth stages and GY, N biomass yield at maturity (NBYM) and GNC were significant (P≤ 0.001), positive and strong/very strong (>r = 0.7). N translocation efficiency (NTE) was inversely related to PANU (~r = ? 0.77, P≤ 0.001), suggesting that N after anthesis is being preferentially transported to the ears to meet the N demand of the growing grains. It is concluded that there is still a large potential for increased NUE by improved N recirculation, use of fast and inexpensive crop N monitoring tools and high yielding, N uptake efficient genotypes.

Abbreviations: NUE, Nitrogen use efficiency; SPAD, Minolta SPAD-502 chlorophyll meter, NHI, nitrogen harvest index; HI, Harvest index; NTE, N translocation efficiency from vegetative plant parts to grain; DMTE, dry matter translocation efficiency; CPAY, contribution of pre-anthesis assimilates to yield; PANU, Post-anthesis N uptake, d.a.s., days after sowing, N0, zero (0) kg ha^?1 applied N fertilizer, N1, 250 kg ha^?1 applied N fertilizer.     

Dissipation of cyproconazole and quinalphos on/in grapes

The persistence of cyproconazole and quinalphos on/in grapes was investigated when both compounds were applied to vines at the locally recommended application frequencies and rates and at double these rates, using commercially available formulations. Residues of cyproconazole applied at recommended and double the recommended rates of application in/on grapes immediately after the last application were 0-049 (±0.034) and 0.077 (±0.008) mg kg^?1, respectively, reduced to 0.011 (±0.003) and 0.018 (±0.010) mg kg^?1 respectively seven days after the last application. The corresponding residue levels of quinalphos immediately following the last application were 1.42 (±0.10) and 3.36 (±0.07) mg kg^?1, reduced to 0.043 (±0.002) and 0.072 (±0.028) mg kg^?1 respectively 21 days after the last application. Cyproconazole, being systemic, is rapidly absorbed by the grape tissues and its residues dissipate with a half-life of three to four days, while quinalphos, being non-systemic, dissipates faster with a half-life of two or three days. The residues of both pesticides were analysed by a GLC-NPD system.     

Exploration of Betalains and Determination of the Antioxidant and Cytotoxicity Profile of Orange and Purple Opuntia spp. Cultivars in Greece

Plant Foods for Human Nutrition - Replacing synthetic dyes with natural pigments has gained great attention over the past years in the food industry, due to the increased alertness of consumers for...